Chapter XXI: Part III: Zoological Geography (1)

_A REVIEW OF THE CHIEF FORMS OF ANIMAL LIFE IN THE SEVERAL REGIONS AND SUB-REGIONS, WITH THE INDICATIONS THEY AFFORD OF GEOGRAPHICAL MUTATIONS._

{173}CHAPTER IX.

THE ORDER OF SUCCESSION OF THE REGIONS.--COSMOPOLITAN GROUPS OF ANIMALS.--TABLES OF DISTRIBUTION.

Having discussed, in our First Part, such general and preliminary matters as are necessary to a proper comprehension of our subject; and having made ourselves acquainted, in our Second Part, with the most important results of Palæontology, we now come to our more immediate subject, which we propose to treat first under its geographical aspect. Taking each of our six regions in succession, we shall point out in some detail the chief zoological features they present, as influenced by climate, vegetation, and other physical features. We shall then treat each of the sub-regions by itself, as well as such of the islands or other sub-divisions as present features of special interest; endeavouring to ascertain their true relations to each other, and the more important changes of physical geography that seem necessary to account for their present zoological condition.

_Order of Succession of the Regions._--We may here explain the reason for taking the several regions in a different succession from that in which they appear in the tabular or diagrammatic headings to each family, in the Fourth, and concluding part of this work. It will have been seen, by our examination of extinct animals (and it will be made still clearer during our study of the several regions) that all the chief types of animal life appear to have originated in the great north temperate or northern continents; while the southern continents--now represented by {174}South America, Australia, and South Africa with Madagascar--have been more or less completely isolated, during long periods, both from the northern continent and from each other. These latter countries have, however, been subject to more or less immigration from the north during rare epochs of approximation to, or partial union with it. In the northern, more extensive, and probably more ancient land, the process of development has been more rapid, and has resulted in more varied and higher types; while the southern lands, for the most part, seem to have produced numerous diverging modifications of the lower grades of organization, the original types of which they derived either from the north, or from some of the ancient continents in Mesozoic or Palæozoic times. Hence those curious resemblances in the fauna of South America, Australia, and, to a less extent, Madagascar, which have led to a somewhat general belief that these distant countries must at one time or other have been united; a belief which, after a careful examination of all the facts, does not seem to the author of this work to be well founded. On the other hand, there is the most satisfactory evidence that each southern region has been more or less closely united (during the tertiary or later secondary epoch) with the great northern continents, leading to numerous resemblances and affinities in their productions.

In endeavouring to present at a glance in the most convenient manner, the distribution of the families in the several regions and sub-regions, it was necessary to arrange them, so that those whose relations to each other were closest should stand side by side; the first and last being those between which the relations were least numerous and least important. Influenced by the usual opinions as to the relations between Australia and South America, the series was at first begun with the Nearctic, and terminated with the Australian and Neotropical regions; and it was not till the whole of the vertebrate families had been gone through, and their distribution carefully studied, that these last two regions were seen to be really wider apart than any others of the series. It was therefore decided to alter the arrangement, beginning with the Neotropical, and ending with the Australian {175}regions; and a careful inspection of the diagrams themselves, taken in their entirety, will, it is believed, show that this is the most natural plan, and most truly exhibits the relations of the several regions.

In the portion of our work now commencing, we are not, however, by any means bound to begin at either end of this series. Each region is studied by itself, but reference will often have to be made to all the other regions; and wherever we begin, we must occasionally refer to facts which will be given further on. As, however, the great northern continents form the central mass from which the southern regions, as it were, diverge, and as the Palæarctic region is both more extensive and much better known than any other, it undoubtedly forms the most convenient starting-point for our proposed survey of the zoological history of the earth. We thus pass from the better known to the less known--from Europe to Africa and tropical Asia, and thence to Australia, completing the series of regions of the Eastern Hemisphere. Beginning again with the Neotropical region, we pass to the Nearctic, which has such striking relations with the preceding and with the Palæarctic region, that it can only be properly understood by constant reference to both. We thus keep separate the Eastern and Western hemispheres, which form, from our point of view, the most radical and most suggestive division of terrestrial faunas; and as we are able to make this also the dividing point of our two volumes, reference to the work will be thereby facilitated.

_Cosmopolitan Groups._--Before proceeding to sketch the zoological features of the several Regions it will be well to notice those family groups which belong to the earth as a whole, and which are so widely and universally distributed over it that it will be unnecessary, in some cases, to do more than refer to them under the separate geographical divisions.

The only absolutely cosmopolitan families of Mammalia are those which are aerial or marine; and this is one of the striking proofs that their distribution has been effected by natural causes, and that the permanence of barriers is one of the chief {176}agencies in the limitation of their range. Even among the aerial bats, however, only one family--the Vespertilionidæ--is truly cosmopolitan, the others having a more or less restricted range. Neither are the Cetacea necessarily cosmopolitan, most of the families being restricted either to warm or to cold seas; but one family, the dolphins (Delphinidæ), is truly so. This order however will not require further notice, as, being exclusively marine the groups do not enter into any of our terrestrial regions. The only other family of mammals that may be considered to be cosmopolitan, is the Muridæ (rats and mice); yet these are not entirely so, since none are known to be truly indigenous in any part of the Australian region except Australia itself.

In the class of Birds, a number of families are cosmopolites, if we reckon as such all which are found in each region and sub-region; but several of these are so abundant in some parts, while they are so sparingly represented in others, that they cannot fairly be considered so. We shall confine that term therefore, to such as, there is reason to believe, inhabit every important sub-division of each region. Such are, among the Passerine birds the crows (Corvidæ), and swallows (Hirundinidæ); among the Picariæ the kingfishers (Alcedinidæ); among other Land birds the pigeons (Columbidæ), grouse and partridges (Tetraonidæ), hawks (Falconidæ), and owls (Strigidæ); among the Waders the rails (Rallidæ), snipes (Scolopacidæ), plovers (Charadriadæ), and herons (Ardeidæ); and among the Swimmers the ducks (Anatidæ), gulls (Laridæ), petrels (Procellariidæ), pelicans (Pelecanidæ), and grebes (Podicipidæ).

In the class of Reptiles there are few absolutely cosmopolitan families, owing to the scarcity of members of this group in some insular sub-regions, such as New Zealand and the Pacific Islands. Those which are most nearly so are the Colubridæ among snakes, and the Scincidæ among lizards.

There is no cosmopolitan family of Amphibia, the true frogs (Ranidæ) being the most widely distributed.

Neither is any family of Freshwater Fishes cosmopolitan, the Siluridæ, which have the widest range, being confined {177}to warm regions, and becoming very scarce in the temperate zones.

Among the Diurnal and Crepuscular Lepidoptera (butterflies and sphinges) the following families are cosmopolitan:--Satyridæ, Nymphalidæ, Lycænidæ, Pieridæ, Papilionidæ, Hesperidæ, Zygænidæ, and Sphingidæ.

Of the Coleoptera almost all, except some of the small and obscure families, are cosmopolitan.

Of the terrestrial Mollusca, the Helicidæ alone are true cosmopolites.

_Tables of Distribution of Families and Genera._--Having been obliged to construct numerous tables of the distribution of the various groups for the purposes of the descriptive part of the work, I have thought it well to append the most important of them, in a convenient form, to the chapter on each region; as much information will thereby be given, which can only be obtained from existing works at the cost of great labour. All these tables are drawn up on a uniform plan, the same generic and family names being used in each; and all are arranged in the same systematic order, so as to be readily comparable with each other. This, although it seems a simple and natural thing to do, has involved a very great amount of labour, because hardly two authors use the same names or follow the same arrangement. Hence comparison between them is impossible, till all their work has been picked to pieces, their synonymy unravelled, their differences accounted for, and the materials recast; and this has to be done, not for two or three authors only, but for the majority of those whose works have been consulted on the zoology of any part of the globe.

Except in the two higher orders--Mammalia and Birds--materials do not exist for complete tables of the genera brought down to the present time. We have given therefore, first, a complete table of all the families of Vertebrata and Diurnal Lepidoptera found in each region, showing the sub-regions in which they occur, and their range beyond the limits of the region. Families which are wholly peculiar to the region, or {178}very characteristic and almost exclusively confined to it, are in _italics_. The number prefixed to each family corresponds to that of the series of families in the Fourth Part of this work, so that if further information is required it can be readily referred to without consulting the index. Names inclosed in parentheses--( . . . ) thus--indicate families which only just enter a region from an adjacent one, to which they properly belong. The eye is thus directed to the more, and the less important families; and a considerable amount of information as to the general features of the zoology of the region, is conveyed in the easiest manner.

The tables of genera of Mammalia and Birds, are arranged on a somewhat different plan. Each genus is given under its Family and Order, and they follow in the same succession in all the tables. The number of species of each genus, inhabiting the region, is given as nearly as can be ascertained; but in many cases this can only be a general approximation. The distribution of the genera within the region, is then given with some detail; and, lastly, the range of the genus beyond the region is given in general terms, the words "Oriental," "Ethiopian," &c., being used for brevity, to indicate that the genus occurs over a considerable part of such regions. Genera which are restricted to the region (or which are very characteristic of it though just transgressing its limits) are given in _italics_; while those which only just enter the region from another to which they really belong, are enclosed in parentheses--( . . . ) thus. The genera are here numbered consecutively, in order that the number of genera in each family or each order, in the region, may be readily ascertained (by one process of subtraction), and thus comparisons made with other regions or with any other area. As the tables of birds would be swelled to an inconvenient length by the insertion in each region of all the genera of Waders and Aquatics, most of which have a very wide range and would have to be repeated in several or all the regions, these have been omitted; but a list has been given of such of the genera as are peculiar to, or highly characteristic of each region.

As this is the first time that any such extensive tables of {179}distribution have been constructed for the whole of the Mammalia and Birds, they must necessarily contain many errors of detail; but with all their imperfections it is believed they will prove very useful to naturalists, to teachers, and to all who take an intelligent interest in the wider problems of geography and natural history.

{180}CHAPTER X.

THE PALÆARCTIC REGION.

This region is of immense extent, comprising all the temperate portions of the great eastern continents. It thus extends from the Azores and Canary Islands on the west to Japan on the east, a distance not far short of half the circumference of the globe. Yet so great is the zoological unity of this vast tract, that the majority of the genera of animals in countries so far removed as Great Britain and Northern Japan are identical. Throughout its northern half the animal productions of the Palæarctic region are very uniform, except that the vast elevated desert-regions of Central Asia possess some characteristic forms; but in its southern portion, we find a warm district at each extremity with somewhat contrasted features. On the west we have the rich and luxuriant Mediterranean sub-region, possessing many peculiar forms of life, as well as a few which are more especially characteristic of the Ethiopian region. On the east we have the fertile plains of Northern China and the rich and varied islands of Japan, possessing a very distinct set of peculiar forms, with others belonging to the Oriental region, into which this part of the Palæarctic region merges gradually as we approach the Tropic of Cancer. Thus, the countries roughly indicated by the names--Northern Europe, the Mediterranean district, Central and Northern Asia, and China with Japan--have each well-marked minor characteristics which entitle them to the rank of sub-regions. Their boundaries are often indefinable; and those here adopted have been fixed upon to some extent by considerations of convenience, dependent on custom and on the more or less perfect knowledge we possess of some of the intervening countries.

{181}_Zoological Characteristics of the Palæarctic Region._--The Palæarctic region has representatives of thirty-five families of mammalia, fifty-five of birds, twenty-five of reptiles, nine of amphibia, and thirteen of freshwater fishes. Comparing it with the only other wholly temperate region, the Nearctic, we find a much greater variety of types of mammalia and birds. This may be due in part to its greater area, but more, probably, to its southern boundary being conterminous for an enormous distance with two tropical regions, the Ethiopean and Oriental; whereas the Nearctic has a comparatively short southern boundary conterminous with the Neotropical region only. This is so very important a difference, that it is rather a matter of surprise that the two north temperate regions should not be more unequal in the number of their higher vertebrate forms, than they actually are.

It is also to the interblending of the Palæarctic with the two adjacent tropical regions, that we must attribute its possession of so few peculiar family groups. These are only three; two of reptiles, _Trogonophidæ_ and _Ophiomoridæ_, and one of fishes, _Comephoridæ_. The number of peculiar genera is, however, considerable, as the following enumeration will show.

_Mammalia._--The monkey of Gibraltar and North Africa, and an allied species found in Japan, are now considered to belong to the extensive eastern genus _Macacus_. The former, however, is peculiar in the entire absence of the tail, and has by many naturalists, been held to form a distinct genus, _Inuus_, confined to the Palæarctic region.

Of bats there are one or two genera (_Barbastellus_, _Plecotus_) which seem to be mainly or wholly Palæarctic, but the classification of these animals is in such an unsettled state that the distribution of the genera is of little importance.

In the next order, Insectivora, we have almost the entire family of the Moles confined to the region. _Talpa_ just enters Northern India; and _Urotrichus_ is common to Japan and {182}North-Western America, but the remaining genera, six in number, are all exclusively Palæarctic.

Among Carnivora we have _Nyctereutes_, the curious racoon-dog of Japan and North-Eastern Asia; _Lutronectes_, an otter peculiar to Japan; and the badger (_Meles_), which ranges over the whole region, and just enters the Oriental region as far as Hongkong; _Æluropus_, a curious form of the Himalayan panda, inhabiting the high mountains of Eastern Thibet; and _Pelagius_, a genus of seals, ranging from the shores of Madeira to the Black Sea.

The Ungulata, or hoofed animals, are still more productive of forms peculiar to this region. First we have the Camels, whose native home is the desert region of Central and Western Asia and Northern Africa, and which, even in their domesticated condition, are confined almost wholly within the limits of the Palæarctic region. Of Deer we have six peculiar genera, _Dama_ and _Capreolus_ found in Europe, with _Elaphodus_, _Lophotragus_, _Hydropotes_, and _Moschus_, confined to Northern China and Mongolia. The great family Bovidæ--comprising the oxen, sheep, goats and antelopes--furnishes no less than seven peculiar Palæarctic genera. These are _Poephagus_, the yak of Thibet; _Addax_, a well-known antelope of Northern Africa and Syria; _Procapra_, _Pantholops_ and _Budorcas_, antelopine genera peculiar to Thibet and Mongolia; with _Rupicapra_ (the chamois), and the extraordinary large-nosed antelope _Saiga_, confined to Europe and Western Asia. Besides these we have _Capra_ (the wild sheep and goats), all the numerous species of which, except two, are exclusively Palæarctic.

Coming to the Rodents, we have again many peculiar forms. Of Muridæ (the mouse and rat tribe), we have six peculiar genera, the more important being _Cricetus_, _Rhombomys Sminthus_, and _Myospalax_. Of Spalacidæ (mole-rats) both the Palæarctic genera, _Ellobius_ and _Spalax_, are peculiar. _Ctenodactylus_, a genus of the South American family Octodontidæ, is found only in North Africa. To these we may add _Myoxus_ (the dormice) and _Lagomys_ (the pikas or tail-less hares) as essentially Palæarctic, since but one species of each genus is found beyond the limits of the region.

_Birds._--It appears to have been the opinion of many {183}naturalists that the Palæarctic region could not be well characterised by its peculiar genera of birds. In Mr. Sclater's celebrated paper already referred to, he remarks, "It cannot be denied that the ornithology of the Palæarctic region is more easily characterised by what it has not than by what it has," and this has been quite recently quoted by Mr. Allen, in his essay on the distribution of North American birds, as if it represented our present knowledge of the subject. But, thanks to the labours of Dr. Jerdon, Mr. Swinhoe, Père David and others, we have now learnt that a large number of birds included in the Indian list, are either mere winter emigrants from Central Asia, or only inhabit the higher ranges of the Himalayas, and thus really belong to the Palæarctic region. The result is, that a host of genera are now seen to be either exclusively or characteristically Palæarctic, and we have no further difficulty in giving positive ornithological characters to the region. In the tables appended to this chapter, all these truly Palæarctic genera will be found printed in _italics_, with an indication of their distribution, which will sometimes be found more fully given under the respective families in the fourth part of this work. Referring to this table for details we shall here summarise the results.

Of the Sylviidæ or warblers, no less than fourteen genera are either exclusively or characteristically Palæarctic, of which _Locustella_, _Sylvia_, _Curruca_ and _Erithacus_ are good examples. Of the oriental family Timaliidæ, the genus _Pterorhinus_ is Palæarctic. Of Panuridæ, or reedlings, there are four peculiar genera (comprising almost the whole family); of Certhiidæ, or creepers, one--_Tichodroma_--which extends southward to the Abyssinian highlands. Of Paridæ, or tits, one--_Acredula_; of Corvidæ, or crows, four--_Pica_ (containing our magpie) being a good example; of Fringillidæ, or finches and buntings, twelve, among which _Acanthis_, _Pyrrhula_ and _Emberiza_ are good illustrations; of Alaudidæ, or larks, there are two peculiar genera. Leaving the Passeres we next come to peculiar forms among the gallinaceous birds: _Syrrhaptes_ among the Pteroclidæ or sand grouse; four genera of Tetraonidæ or grouse and partridges, and five of Phasianidæ or pheasants, comprising some of the most magnificent birds in the world. Lastly {184}among the far-wandering aquatic birds we have no less than five genera which are more especially Palæarctic,--_Ortygometra_, the corn-crake, and _Otis_, the great bustard, being typical examples. We may add to these, several genera almost confined to this region, such as _Garrulus_ (jays), _Fringilla_ (true finches), _Yunx_ (wrynecks) and some others; so that in proportion to its total generic forms a very large number are found to be peculiar or characteristic.

This view, of the high degree of speciality of the Palæarctic region, will no doubt be objected to by some naturalists, on the ground that many of the genera reckoned as exclusively Palæarctic are not so, but extend more or less into other regions. It is well, therefore, to consider what principles should guide us in a matter of this kind, especially as we shall have to apply the same rules to each of the other regions. We may remark first, that the limits of the regions themselves are, when not formed by the ocean, somewhat arbitrary, depending on the average distribution of a number of characteristic forms; and that slight local peculiarities of soil, elevation, or climate, may cause the species of one region to penetrate more or less deeply into another. The land boundary between two regions will be, not a defined line but a neutral territory of greater or less width, within which the forms of both regions will intermingle; and this neutral territory itself will merge imperceptibly into both regions. So long therefore as a species or genus does not permanently reside considerably beyond the possible limits of this neutral territory, we should not claim it as an inhabitant of the adjacent region. A consideration of perhaps more importance arises, from the varying extent of the range of a genus, over the area occupied by the region. Some genera are represented by single species existing only in a very limited area; others by numerous species which occupy, entirely or very nearly, the whole extent of the region; and there is every intermediate grade between these extremes. Now, the small localised genera, are always reckoned as among the best examples of types peculiar to a region; while the more wide-spread groups are often denied that character if they extend a little beyond {185}the supposed regional limits, or send one or two, out of a large number of species, into adjacent regions; yet there is some reason to believe that the latter are really more important as characterising a zoological region than the former. In the case of a single isolated species or genus we have a dying-out group; and we have so many cases of discontinuous species of such groups (of which _Urotrichus_ in Japan and British Columbia, _Eupetes_ in Sumatra and New Guinea are examples), that it is quite as probable as not, that any such isolated species has only become peculiar to the region by the recent extinction of an allied form or forms in some other region. On the other hand, a genus consisting of numerous species ranging over an entire region or the greater part of one, is a dominant group, which has most likely been for some time extending its range, and whose origin dates back to a remote period. The slight extension of such a group beyond the limits of the region to which it mainly belongs, is probably a recent phenomenon, and in that case cannot be held in any degree to detract from its value as one of the peculiar forms of that region.

The most numerous examples of this class, are those birds of the temperate regions which in winter migrate, either wholly or partially, into adjacent warmer countries. This migration most likely began subsequent to the Miocene period, during that gradual refrigeration of the temperate zones which culminated in the glacial epoch, and which still continues in a mitigated form. Most of the genera, and many even of the species of birds which migrate southwards in winter, have therefore, most likely, always been inhabitants of our present Palæarctic and Nearctic regions; permanent residents during warm epochs, but only able now to maintain their existence by migration in winter. Such groups belong truly to the temperate zones, and the test of this is the fact of their not having any, or very few, representatives, which are permanent residents in the adjacent tropical regions. When there are such representative species, we do not claim them as peculiar to the Northern regions. Bearing in mind these various considerations, it will be found that we have been very moderate in our estimate of the number of genera {186}that may fairly be considered as exclusively or characteristically Palæarctic.

_Reptiles and Amphibia._--The Palæarctic region possesses, in proportion to its limited reptilian fauna, a full proportion of peculiar types. We have for instance two genera of snakes, _Rhinechis_ and _Halys_; seven of lizards, _Trigonophis_, _Psammodromus_, _Hyalosaurus_, _Scincus_, _Ophiomorus_, _Megalochilus_, and _Phrynocephalus_; eight of tailed batrachians, _Proteus_, _Salamandra_, _Seiranota_, _Chioglossa_, _Hynobius_, _Onychodactylus_, _Geotriton_, and _Sieboldia_; and eight of tail-less batrachians, _Bombinator_, _Pelobates_, _Didocus_, _Alytes_, _Pelodytes_, _Discoglossus_, _Laprissa_, and _Latonia_. The distribution of these and other Palæarctic genera will be found in our second vol. chap. xix.

_Freshwater Fish._--About twenty genera of freshwater fishes are wholly confined to this region, and constitute a feature which ought not to be overlooked in estimating its claim to the rank of a separate primary division of the earth. They belong to the following families:--Percidæ (three genera), _Acerina_, _Percarina_, _Aspro_; Comephoridæ (one genus), _Comephorus_, found only in Lake Baikal; Salmonidæ (three genera), _Brachymystax_, _Luciotrutta_, and _Plecoglossus_; Cyprinodontidæ (one genus), _Tellia_, found only in Alpine pools on the Atlas Mountains; Cyprinidæ (thirteen genera), _Cyprinus_, _Carassus_, _Paraphoxinus_, _Tinca_, _Achilognathus_, _Rhodeus_, _Chondrostoma_, _Pseudoperilampus_, _Ochetebius_, _Aspius_, _Alburnus_, _Misgurnus_, and _Nemachilus_.

_Summary of Palæarctic Vertebrata._--Summarising these details, we find that the Palæarctic region possesses thirty-five peculiar genera of mammalia, fifty-seven of birds, nine of reptiles, sixteen of amphibia, and twenty-one of freshwater fishes; or a total of 138 peculiar generic types of vertebrata. Of these, 87 are mammalia and land-birds out of a total of 274 genera of these groups; or rather less than one-third peculiar, a number which will serve usefully to compare with the results obtained in other regions.

In our chapter on Zoological Regions we have already pointed out the main features which distinguish the Palæarctic from the Oriental and Ethiopian regions. The details now given will {187}strengthen our view of their radical distinctness, by showing to how considerable an extent the former is inhabited by peculiar, and often very remarkable generic types.

_Insects: Lepidoptera._--The Diurnal Lepidoptera, or butterflies, are not very abundant in species, their number being probably somewhat over 500, and these belong to not more than fifty genera. But no less than fifteen of these genera are wholly confined to the region. Nine of the families are represented, as follows:--1. _Danaidæ_; having only a single species in South Europe. 2. _Satyridæ_; well represented, there being more than 100 species in Europe, and three peculiar genera. 3. _Nymphalidæ_; rather poorly represented, Europe having only about sixty species, but there is one peculiar genus. 4. _Libytheidæ_; a very small family, represented by a single species occurring in South Europe. 5. _Nemeobiidæ_; a rather small family, also having only one species in Europe, but which constitutes a peculiar genera. 6. _Lycænidæ_; an extensive family, fairly represented, having about eighty European species; there are two peculiar genera in the Palæarctic region. 7. _Pieridæ_; rather poorly represented with thirty-two European species; two of the genera are, however, peculiar. 8. _Papilionidæ_; very poorly represented in Europe with only twelve species, but there are many more in Siberia and Japan. No less than five of the small number of genera in this family are wholly confined to the region, a fact of much importance, and which to a great extent redeems the character of the Palæarctic region as regard this order of insects. Their names are _Mesapia_, _Hypermnestra_, _Doritis_, _Sericinus_, and _Thais_; and besides these we have _Parnassius_--the "Apollo" butterflies--highly characteristic, and only found elsewhere in the mountains of the Nearctic region. 9. _Hesperidæ_; poorly represented with about thirty European species, and one peculiar genus.

Four families of _Sphingina_ occur in the Palæarctic region, and there are several peculiar genera.

In the _Zygænidæ_ there are two exclusively European genera, and the extensive genus _Zygæna_ is itself mainly Palæarctic. The small family _Stygiidæ_ has two out of its three genera {188}confined to the Palæarctic region. In the _Ægeriidæ_ the genus _Ægeria_ is mainly Palæarctic. The _Sphingidæ_ have a wider general range, and none of the larger genera are peculiar to any one region.

_Coleoptera._--The Palæarctic region is the richest portion of the globe in the great family of _Carabidæ_, or predacious ground-beetles, about 50 of the genera being confined to it, while many others, including the magnificent genus _Carabus_, have here their highest development. While several of the smaller genera are confined to the eastern or western sub-regions, most of the larger ones extend over the whole area, and give it an unmistakable aspect; while in passing from east to west or _vice-versâ_, allied species and genera replace each other with considerable regularity, except in the extreme south-east, where, in China and Japan, some Oriental forms appear, as do a few Ethiopian types in the south-west.

Cicindelidæ, or tiger-beetles, are but poorly represented by about 70 species of the genus _Cicindela_, and a single _Tetracha_ in South Europe.

Lucanidæ, or stag-beetles, are also poor, there being representatives of 8 genera. One of these, _Æsalus_ (a single species), is peculiar to South Europe, and two others, _Cladognathus_ and _Cyclopthalmus_, are only represented in Japan, China, and Thibet.

Cetoniidæ, or rose-chafers, are represented by 13 genera, two of which are peculiar to South Europe (_Tropinota_ and _Heterocnemis_), while _Stalagmosoma_, ranging from Persia to Nubia, and the fine _Dicranocephalus_ inhabiting North China, Corea, and Nipal, may also be considered to belong to it. The genera _Trichius_, _Gnorimus_, and _Osmoderma_ are confined to the two north temperate regions.

Buprestidæ, or metallic beetles, are rather abundant in the warmer parts of the region, 27 genera being represented, nine of which are peculiar. By far the larger portion of these are confined to the Mediterranean sub-region. A considerable number also inhabit Japan and China.

The Longicorns, or long-horned beetles, are represented by no less than 196 genera, 51 of which are peculiar. They are {189}much more abundant in the southern than the northern half of the region. Several Oriental genera extend to Japan and North China, and a few Ethiopian genera to North Africa. Thirteen genera are confined, to the two north temperate regions. Several large genera, such as _Dorcadion_ (154 species), _Phytæcia_ (85 species), _Pogonochærus_ (22 species), _Agapanthia_ (22 species), and _Vesperus_ (7 species), are altogether peculiar to the Palæarctic region; and with a preponderance of _Leptura_, _Grammoptera_, _Stenocorus_, and several others, strongly characterise it as distinct from the Nearctic and Oriental regions.

The other families which are well developed in the Palæarctic regions, are, the Staphylinidæ or rove-beetles, Silphidæ or burying-beetles, Histeridæ or mimic-beetles, Nitidulidæ, Aphodiidæ, Copridæ (especially in South Europe), Geotrupidæ or dung-beetles, Melolonthidæ or chafers, Elateridæ or click-beetles, the various families of Malacoderms and Heteromera, especially Pimeliidæ in the Mediterranean sub-region, Curculionidæ or weevils, the Phytophaga or leaf-eaters, and Cocinellidæ or lady-birds.

The number of species of Coleoptera in the western part of the Palæarctic region is about 15,000, and there are probably not more than 2,000 to add to this number from Siberia, Japan, and North China; but were these countries as well explored as Europe, we may expect that they would add at least 5,000 to the number above given, raising the Palæarctic Coleopterous fauna to 20,000 species. As the total number of species at present known to exist in collections is estimated (and perhaps somewhat over-estimated) at 70,000 species, we may be sure that were the whole earth as thoroughly investigated as Europe, the number would be at least doubled, since we cannot suppose that Europe, with the Mediterranean basin, can contain more than one-fifth of the whole of the Coleoptera of the globe.

Of the other orders of insects we here say nothing, because in their case much more than in that of the Coleoptera and Lepidoptera, is the disproportion enormous between our knowledge of the European fauna and that of almost all the rest of the globe. {190}They are, therefore, at present of comparatively little use for purposes of geographical distribution, even were it advisable to enter into the subject in a work which will, perhaps, be too much overburdened with details only of interest to specialists.

_Land Shells._--These are very numerous in the warmer parts of the region, but comparatively scarce towards the North. South Europe alone possesses over 600 species, whereas there are only 200 in all Northern Europe and Asia. The total number of species in the whole region is probably about 1,250, of which the great majority are Helicidæ; the Operculated families being very poorly represented. Several small genera or sub-genera are peculiar to the region, as _Testacella_ (West Europe and Canaries); _Leucochroa_ (Mediterranean district); _Acicula_ (Europe); _Craspedopoma_ (Atlantic Islands); _Leonia_ (Algeria and Spain); _Pomatias_ (Europe and Canaries); _Cecina_ (Mongolia). The largest genera are _Helix_ and _Clausilia_, which together comprise more than half the species; _Pupa_, very numerous; _Bulimus_ and _Achatina_ in moderate numbers, and all the rest small. _Helix_ is the only genus which contains large and handsome species; _Bulimus_ and _Achatina_, so magnificent in tropical countries, being here represented by small and obscure forms only. _Daudebardia_ is confined to Central and South Europe and New Zealand; _Glandina_ is chiefly South American; _Hyalina_ is only American and European; _Buliminus_ ranges over all the world except America; and the other European genera of Helicidæ are widely distributed. Of the Operculata, _Cyclotus_, _Cyclophorus_, and _Pupina_ extend from the Oriental region into Japan and North China; _Tudoria_ is found in Algeria and the West Indies; _Hydrocena_ is widely scattered, and occurs in South Europe and Japan. The genera of freshwater shells are all widely distributed.

THE PALÆARCTIC SUB-REGIONS.

The four sub-regions which are here adopted, have been fixed upon as those which are, in the present state of our knowledge, at once the most natural and the only practicable ones. {191}No doubt all of them could be advantageously again subdivided, in a detailed study of the geographical distribution of _species_. But in a general work, which aims at treating all parts of the world with equal fulness, and which therefore is confined almost wholly to the distribution of families and genera, such further subdivision would be out of place. It is even difficult, in some of the classes of animals, to find peculiar or even characteristic genera for the present sub-regions; but they all have well marked climatic and physical differences, and this leads to an assemblage of species and of groups which are sufficiently distinctive.

_I. Central and Northern Europe._

This sub-region, which may perhaps be termed the "European," is zoologically and botanically the best known on the globe. It can be pretty accurately defined, as bounded on the south by the Pyrenees, the Alps, the Balkans, the Black Sea, and the Caucasus range; and by the Ural Mountains, or perhaps more correctly the valley of the Irtish and Caspian Sea, on the east; while Ireland and Iceland are its furthest outliers in the west. To the north, it merges so gradually into the Arctic zone that no demarcation is possible. The great extent to which this sub-region is interpenetrated by the sea, and the prevalence of westerly winds bringing warmth and moisture from an ocean influenced by the gulf-stream, give it a climate for the most part genial, and free from extremes of heat and cold. It is thus broadly distinguished from Siberia and Northern Asia generally, where a more extreme and rigorous climate prevails.

The whole of this sub-region is well watered, being penetrated by rivers in every direction; and it consists mainly of plains and undulating country of moderate elevation, the chief mountain ranges being those of Scandinavia in the north-west, and the extensive alpine system of Central Europe. But these are both of moderate height, and a very small portion of their surface is occupied either by permanent snow-fields, or by barren uplands inimical to vegetable and animal life. It is, in {192}fact, to these, and the numerous lesser mountains and hills which everywhere diversify the surface of Europe, that the variety and abundance of its animal life is greatly due. They afford the perennial supplies to rivers, and furnish in their valleys and ever varying slopes, stations suited to every form of existence. A considerable area of Central Europe is occupied by uplands of moderate elevation, a comparatively small portion being flat and marshy plains.

Most of the northern and much of the central portions of Europe are covered with vast forests of coniferous trees; and these, occupying as they do those tracts where the winter is most severe, supply food and shelter to many animals who could not otherwise maintain their existence. It is probable that the original condition of the greater part, if not the whole, of temperate Europe, except the flat marshes of the river valleys and the sandy downs of the coast, was that of woodland and forest, mostly of deciduous trees, but with a plentiful admixture of such hardy evergreens as holly, ivy, privet, and yew. A sufficient proportion of these primeval woods, and of artificial plantations which have replaced them, fortunately remain, to preserve for us most of the interesting forms of life, which were developed before man had so greatly modified the surface of the earth, and so nearly exterminated many of its original tenants. Almost exactly in proportion to the amount of woodland that still remains in any part of Europe, do we find (other things being equal) the abundance and variety of wild animals; a pretty clear indication that the original condition of the country was essentially that of a forest, a condition which only now exists in the thinly inhabited regions of the north.

Although the sub-region we are considering is, for its extent and latitude, richly peopled with animal life, the number of genera altogether peculiar to it is not great. There are, however, several which are very characteristic, and many species, both of the smaller mammalia and of birds, are wholly restricted to it.

_Mammalia._--The genera wholly confined to this sub-region are {193}only two. _Myogale_, the desman, is a curious long-snouted Insectivorous animal somewhat resembling the water-rat in its habits. There are two species, one found only on the banks of streams in the French Pyrenees, the other on the great rivers of Southern Russia. The other peculiar genus, _Rupicapra_ (the chamois of the Alps), is found on all the high mountains of Central Europe. Almost peculiar are _Spalax_ (the mole-rat) found only in Eastern Europe and Western Siberia; and _Saiga_, an extraordinary large-nosed antelope which has a nearly similar distribution. Highly characteristic forms, which inhabit nearly every part of the sub-region, are, _Talpa_ (the mole), _Erinaceus_, (the hedgehog), _Sorex_ (the shrew), _Meles_ (the badger), _Ursus_ (the bear), _Canis_ (the wolf and fox), _Mustela_ (the weasel), _Lutra_ (the otter), _Arvicola_ (the vole), _Myoxus_ (the dormouse), and _Lepus_ (the hare and rabbit); while _Bos_ (the wild bull) was, until exterminated by man, no doubt equally characteristic. Other genera inhabiting the sub-region will be found in the list given at the end of this chapter.

_Birds._--It is difficult to name the birds that are most characteristic of this sub-region, because so many of the most familiar and abundant are emigrants from the south, and belong to groups that have a different range. There is perhaps not a single genus wholly confined to it, and very few that have not equal claims to be placed elsewhere. Among the more characteristic we may name _Turdus_ (the thrushes), _Sylvia_ (the warblers), _Panurus_ (the reedling), _Parus_ (the tits), _Anthus_ (the pipits), _Motacilla_ (the wagtails), which are perhaps more abundant here than in any other part of the world, _Emberiza_ (the buntings), _Plectrophanes_ (the snow buntings), _Passer_ (the house sparrows), _Loxia_ (the crossbills), _Linota_ (the linnets), _Pica_ (the magpies), _Tetrao_ (grouse), _Lagopus_ (ptarmigan) and many others.

I am indebted to Mr. H. E. Dresser, who is personally acquainted with the ornithology of much of the North of Europe, for some valuable notes on the northern range of many European birds. Those which are characteristic of the extreme Arctic zone, extending beyond 70° north latitude, and tolerably abundant, are two falcons (_Falco gyrfalco_ and _F. peregrinus_); {194}the rough-legged buzzard (_Archibuteo lagopus_); the snowy owl (_Nyctea scandiaca_); the raven (_Corvus corax_); three buntings (_Emberiza schæniculus_, _Plectrophanes nivalis_ and _P. calcarata_); a lark (_Otocorys alpestris_); several pipits, the most northern being _Anthus cervinus_; a wagtail (_Budytes cinereocapilla_); a dipper (_Cinclus melanogaster_); a warbler (_Cyanecula suecica_); the wheatear (_Saxicola oenanthe_); and two ptarmigans (_Lagopus albus_ and _L. salicetus_). Most of these birds are, of course, only summer visitors to the Arctic regions, the only species noted as a permanent resident in East Finmark (north of latitude 70°) being the snow-bunting (_Plectrophanes nivalis_).

The birds that are characteristic of the zone of pine forests, or from about 61° to 70° north latitude, are very numerous, and it will be sufficient to note the genera and the number of species (where more than one) to give an idea of the ornithology of this part of Europe. The birds of prey are, _Falco_ (three species), _Astur_ (two species), _Buteo_, _Pandion_, _Surnia_, _Bubo_, _Syrnium_, _Asio_, _Nyctala_. The chief Passerine birds are, _Corvus_ (two species), _Pica_, _Garrulus_ (two species), _Nucifraga_, _Bombycilla_, _Hirundo_ (two species), _Muscicapa_ (two species), _Lanius_, _Sturnus_, _Passer_ (two species), _Pyrrhula_, _Carpodacus_, _Loxia_ (two species), _Pinicola_, _Fringilla_ (eight species), _Emberiza_ (five species), _Alauda_, _Anthus_, _Turdus_ (five species), _Ruticilla_, _Pratincola_, _Accentor_, _Sylvia_ (four species), _Hypolais_, _Regulus_, _Phylloscopus_ (two species), _Acrocephalus_, _Troglodytes_, and _Parus_ (six species). Woodpeckers are abundant, _Picus_ (four species), _Gecinus_, and _Yunx_. The kingfisher (_Alcedo_), goatsucker (_Caprimulgus_), and swift (_Cypselus_) are also common. The wood-pigeon (_Columba_) is plentiful. The gallinaceous birds are three grouse, _Tetrao_ (two species) and _Bonasa_, and the common quail (_Coturnix_).

The remaining genera and species of temperate or north-European birds, do not usually range beyond the region of deciduous trees, roughly indicated by the parallel of 60° north latitude.

Plate I.

THE ALPS OF CENTRAL EUROPE, WITH CHARACTERISTIC ANIMALS.

{195}_Plate I.--Illustrating the Zoology of Central Europe._--Before considering the distribution of the other classes of vertebrata, it will be convenient to introduce our first illustration, which represents a scene in the Alps of Central Europe, with figures of some of the most characteristic Mammalia and Birds of this sub-region. On the left is the badger (_Meles Taxus_) one of the weasel family, and belonging to a genus which is strictly Palæarctic. It abounds in Central and Northern Europe and also extends into North Asia, but is represented by another species in Thibet and by a third in Japan. The elegantly-formed creatures on the right are chamois (_Rupicapra tragus_), almost the only European antelopes, and wholly confined to the higher mountains, from the Pyrenees to the Carpathians and the Caucasus. The chamois is the only species of the genus, and is thus perhaps the most characteristic European mammal. The bird on the left, above the badgers, is the Alpine chough, (_Fregilus pyrrhocorax_). It is found in the high mountains from the Alps to the Himalayas, and is allied to the Cornish chough, which is still found on our south-western coasts, and which ranges to Abyssinia and North China. The Alpine chough differs in having a shorter bill of an orange colour, and vermilion red feet as in the other species. In the foreground are a pair of ruffs (_Machetes pugnax_) belonging to the Scolopacidæ or snipe family, and most nearly allied to the genus _Tringa_ or sandpiper. This bird is remarkable for the fine collar of plumes which adorns the males in the breeding season, when they are excessively pugnacious. It is the only species of its genus, and ranges over all Europe and much of Northern Asia, migrating in the winter to the plains of India, and even down the east coast of Africa as far as the Cape of Good Hope; but it only breeds in the Palæarctic region, over the greater part of which it ranges.

_Reptiles and Amphibia._--There are no genera of reptiles peculiar to this sub-region. Both snakes and lizards are comparatively scarce, there being about fourteen species of the former and twelve of the latter. Our common snake (_Tropidonotus natrix_) extends into Sweden and North Russia, but the viper (_Viperus berus_) goes further north, as far as Archangel (64° N.), and in Scandinavia (67° N.), and is the most Arctic of all known {196}snakes. Of the lizards, _Lacerta stirpium_ (the sand lizard) has the most northerly range, extending into Poland and Northern Russia; and _Anguis fragilis_ (the blind or slow-worm) has almost an equal range.

Amphibia, being more adapted to a northern climate, have acquired a more special development, and thus several forms are peculiar to the North European sub-region. Most remarkable is _Proteus_, a singular eel-like aquatic creature with small legs, found only in the subterranean lakes in Carniola and Carinthia; _Alytes_, a curious toad, the male of which carries about the eggs till they are hatched, found only in Central Europe from France to the east of Hungary; and _Pelodytes_, a frog found only in France. Frogs and toads are very abundant all over Europe, the common frog (_Rana temporaria_) extending to the extreme north. The newts (_Triton_) are also very abundant and widely spread, though not ranging so far north as the frogs. The genera _Bombinator_ (a toad-like frog), and _Hyla_ (the tree frog) are also common in Central Europe.

_Freshwater Fish._--Two genera of the perch family (Percidæ) are peculiar to this sub-region,--_Percarina_, a fish found only in the river Dniester, and _Aspro_, confined to the rivers of Central Europe. Of the very characteristic forms are, _Gasterosteus_ (stickle-back), which alone forms a peculiar family--Gasterosteidæ; _Perca_, _Acerina_ and _Lucioperca_, genera of the perch family; _Silurus_, a large fish found in the rivers of Cenrtal Europe, of the family Siluridæ; _Esox_ (the pike), of the family Esocidæ; _Cyprinus_ (carp), _Gobio_ (gudgeon), _Leuciscus_ (roach, chub, dace, &c.), _Tinca_ (tench), _Abramus_ (bream), _Alburnus_ (bleak), _Cobitis_ (loach), all genera of the family Cyprinidæ.

_Insects--Lepidoptera._--No genera of butterflies are actually confined to this sub-region, but many are characteristic of it. _Parnassius_, _Aporia_, _Leucophasia_, _Colias_, _Melitæa_, _Argynnis_, _Vanessa_, _Limenitis_, and _Chionobas_, are all very abundant and widespread, and give a feature to the entomology of most of the countries included in it.

_Coleoptera._--This sub-region is very rich in Carabidæ; the genera _Elaphrus_, _Nebria_, _Carabus_, _Cychrus_, _Pterostichus_, _Amara_, {197}_Trechus_ and _Peryphus_ being especially characteristic. Staphylinidæ abound. Among Lamellicorns the genus _Aphodius_ is most characteristic. Buprestidæ are scarce; Elateridæ more abundant. Among Malacoderms _Telephorus_ and _Malachius_ are characteristic. Curculionidæ abound: _Otiorhyuchus_, _Omias_, _Erirhinus_, _Bagous_, _Rhynchites_ and _Ceutorhynchus_ being very characteristic genera. Of Longicorns _Callidium_, _Dorcadion_, _Pogonochærus_, _Pachyta_ and _Leptura_ are perhaps the best representatives. _Donacia_, _Crioceris_, _Chrysomela_, and _Altica_, are typical Phytophaga; while _Coccinella_ is the best representative of the Securipalpes.

_North European Islands._--The British Islands are known to have been recently connected with the Continent, and their animal productions are so uniformly identical with continental species as to require no special note. The only general fact of importance is, that the number of species in all groups is much less than in continental districts of equal extent, and that this number is still farther diminished in Ireland. This may be accounted for by the smaller area and less varied surface of the latter island; and it may also be partly due to the great extent of low land, so that a very small depression would reduce it to the condition of a cluster of small islands capable of supporting a very limited amount of animal life. Yet further, if after such a submergence had destroyed much of the higher forms of life in Great Britain and Ireland, both were elevated so as to again form part of the Continent, a migration would commence by which they would be stocked afresh; but this migration would be a work of time, and it is to be expected that many species would never reach Ireland or would find its excessively moist climate unsuited to them.

Some few British species differ slightly from their continental allies, and are considered by many naturalists to be distinct. This is the case with the red grouse (_Lagopus scoticus_) among birds; and a few of the smaller Passeres have also been found to vary somewhat from the allied forms on the Continent, showing that the comparatively short interval since the glacial period, and the slightly different physical conditions dependent on {198}insularity, have sufficed to commence the work of specific modification. There are also a few small land-shells and several insects not yet found elsewhere than in Britain; and even one of the smaller Mammalia--a shrew (_Sorex rusticus_). These facts are all readily explained by the former union of these islands with the Continent, and the alternate depressions and elevations which are proved by geological evidence to have occurred, by which they have been more than once separated and united again in recent times. For the evidence of this elevation and depression, the reader may consult Sir Charles Lyell's _Antiquity of Man_.

Iceland is the only other island of importance belonging to this sub-region, and it contrasts strongly with Great Britain, both in its Arctic climate and oceanic position. It is situated just south of the Arctic circle and considerably nearer Greenland than Europe, yet its productions are almost wholly European. The only indigenous land mammalia are the Arctic fox (_Canis lagopus_), and the polar bear as an occasional visitant, with a mouse (_Mus islandicus_), said to be of a peculiar species. Four species of seals visit its shores. The birds are more interesting. According to Professor Newton, ninety-five species have been observed; but many of these are mere stragglers. There are twenty-three land, and seventy-two aquatic birds and waders. Four or five are peculiar species, though very closely related to others inhabiting Scandinavia or Greenland. Only two or three species are more nearly related to Greenland birds than to those of Northern Europe, so that the Palæarctic character of the fauna is unmistakable. The following lists, compiled from a paper by Professor Newton, may be interesting as showing more exactly the character of Icelandic ornithology.

1. Peculiar species.--_Troglodytes borealis_ (closely allied to the common wren, found also in the Faroe Islands); _Falco islandicus_ (closely allied to _F. gyrfalco_); _Lagopus islandorum_ (closely allied to _L. rupestris_ of Greenland).

2. European species resident in Iceland.--_Emberiza nivalis_, _Corvus corax_, _Haliæetus albicilla_, _Rallus aquaticus_, _Hæmatopus ostralegus_, _Cygnus ferus_, _Mergus_ (two species), _Phalacocorax_ (two {199}species), _Sula bassana_, _Larus_ (two species), _Stercorarius catarractes_, _Puffinus anglorum_, _Mergulus alle_, _Uria_ (three species), _Alca torda_.

3. American species resident in Iceland.--_Clangula islandica_, _Histrionicus torquatus_.

4. Annual visitants from Europe.--_Turdus iliacus_, _Ruticilla tithys_, _Saxicola ænanthe_, _Motacilla alba_, _Anthus pratensis_, _Linota linaria_, _Chelidon urbica_, _Hirundo rustica_, _Falco æsalon_, _Surnia nyctea_, _Otus brachyotus_, _Charadrius pluvialis_, _Ægialites hiaticula_, _Strepsilas interpres_, _Phalaropus fulicarius_, _Totanus calidris_, _Limosa_ (species), _Tringa_ (three species), _Calidris arenaria_, _Gallinago media_, _Numenius phæopus_, _Ardea cinerea_, _Anser_ (two species), _Bernicla_ (two species), _Anas_ (four species), _Fuligula marila_, _Harelda glacialis_, _Somateria mollissima_, _Oedemia nigra_, _Sterna macrura_, _Rissa tridactyla_, _Larus luecopterus_, _Stercorarius_ (two species), _Fratercula artica_, _Colymbus_ (two species), _Podiceps cornutus_.

5. Annual visitant from Greenland.--_Falco candicans_.

6.--Former resident, now extinct.--_Alca impennis_ (the great auk).

_II.--Mediterranean Sub-region._