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Full text of "Animal geography, the faunas of the natural regions of the Globe"

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^oor 

^ THE OXFORD GEOGRAPHIES 

Edited by A. J. HERBERTSON 

ANIMAL GEOGRAPHY 

THE FAUNAS OF THE NATURAL 
REGIONS OF THE GLOBE 



MARION I. NEWBIGIN 

D.Sc. (liOND.) 

LECTURER IN ZOOLOGY AND HIOLOGY IN THE EDINBURGH SCHOOL OF 

MEDICINE rOR WOMEN 

EDITOR or THE ' SCOTTISH GEOGRAPHICAL MAGAZINE* 




OXFORD 

AT THE CLARENDON PRESS 

1913 



OXFORD UNIVERSITY PRESS 

LONDON EDINBURGH GLASGOW NEW YOKK 
TORONTO MELBOURNE BOMBAY 

HUMPHREY MILFORD M.A. 

PUBLISHER TO THE UNIVERSITY 



PREFACE 

Within the last few years, as is well known, botanical 
geography has made great strides. The intimate rela- 
tion between the vegetative covering and the physical 
conditions has been in many cases thoroughly worked 
out, and all the more modern geographical text-books 
give at least some indication of the results obtained. 
On the other hand, the more difficult subject of the 
relation between the animals of the various natural 
regions and their surroundings has been much less 
fully treated by geographers. The facts have still 
mostly to be sought in zoological text-books, where 
they are treated from another point of view, and many 
even of the most recent geographical text-books show 
uncertainty of treatment when dealing with the 
animals of tropical forest and arctic tundra. The 
present book is an attempt to put the main facts 
connected with the distribution of animals in a form 
acceptable to the geographical student, and has been 
written by one whose approach to geography was first 
made from the biological side. 

The sources of the illustrations are indicated beneath 
each, and I am greatly indebted to the various 
gentlemen named for permission to reproduce their 
photographs. Special acknowledgement should be 
made to Sir Thomas Carlaw Martin, Director of 



4 PREFACE 

the Royal Scottish Museum, and Mr. Eagle Clarke, 
Keeper of the Natural History Collection there, for 
permission to photograph a number of specimens in 
the collection. 

For the index I am indebted to my sister, Miss 
Florence Newbigin. 

I^L^RION I. NEWBIGIN. 

Edinburgh, 1913. 



CONTENTS 



PAGE 

Iniroduction : The Natural Regions of the Globe . 9 

CHAPTER 

I. The Tundra and its Fauna .... 15 

II. The Taiga, or Coniferous Forest, and its Fauna , 36 

III. Steppe Faunas and the Temperate Steppes of 

Asia and North America .... 52 

IV. Mountain Faunas -72 

V. The Fauna of the Tropical Forest ... 92 

VI. Tropical Savanas and Deserts . . . .121 

VII. Special Features of Island Faunas . . . 144 

VIII. The Distribution of Animal Life in the Sea . 156 

IX. The Animals of Lakes and Rivers, Cave Faunas 182 



x. zoogeooraphical regions . 
Appendix. Outline Classification of Animals 
Index 



208 
226 
231 



Digitized by the Internet Archive 

in 2007 with funding from 

IVIicrosoft Corporation 



http://www.archive.org/details/animalgeographyfOOnewbuoft 



LIST OF ILLUSTRATIONS 



FIG. 








PAGE 


1. Tundra in Northern Russia ..... 19 


2. Ptarmigan ..... 






. 25 


3. Wapiti .... 








. 39 


4. Elk 








facing 40 


5. Virginian Deer . 








41 


6. Three-toed Woodpecker 








48 


7. Camels 








. 61 


8. American Bison . 








facing 62 


9. Prairie Marmot . 








63 


10. Sage-cock . 








. 70 


11. Swiss Alp . 








74 


12. Snow Leopard . 








facing 80 


13. Yak .... 








81 


14. Alaskan Wild Sheep . 








82 


15. Takin 








83 


16. Kiang 








83 


17. Bharal 








84 


18. Serow 








84 


19. Musk-deer . 








85 


20. Hyrax 








86 


21. Rain-forest in North Borne 


3 






98 


22. Congo Tropical Forest 








99 


23. Red Howling Monkey 








100 


24. American Monkey 








101 


25. Black Lemur 








102 


26. Puma and Cubs 








108 


27. African Elephant 








109 


28. Indian Elephant 








. 109 


29. African Flying Squirrel 








facing 1 10 


30. BraziUan Tree Porcupine 








» 111 


31. Quica Opossum . 








111 


32. Sloth 








112 


33. Phalanger . 








113 


34. Savana 








. 122 



LIST OF ILLUSTRATIONS 



no. 






PAGE 


35. Gnu facing 130 


36. Giraffe .... 






131 


37. Jerboa (Central Asia) . 






134 


38. Jerboa (Egypt) . 






134 


39. Cactus Wren 






. 141 


40. Kiwi 






facing 150 


41. Seal Rookery in Copper Island 






„ ' 162 


42. Seals on shore of Copper Island 






163 


43. Kittiwake Gulls . 






. 164 


44. Penguins .... 






facing 164 


45. Clouded Leopard 






218 


46. Okapi .... 






219 


47. Bower Bird 






224 


48. Lyre Bird .... 






225 



INTRODUCTION 

THE NATURAL REGIONS OF THE GLOBE 

The modern interest in the facts of the distribution 
of animals, as indeed the modern interest in so many 
of the problems connected with biology, dates from 
the publication of the Origin of Species. Darwin in his 
famous voyage on the Beagle was much struck by the 
curious phenomena of distribution which that voyage 
broitght before his eyes, and it was these phenomena 
which helped to direct his attention to that line of 
thought which resulted ultimately in the publication 
of his theory of Natural Selection. The two facts which 
especially struck him were the two set forth in the 
chapters on distribution in the Origin of Species. These 
are, first, that similarity of physical conditions does not 
necessarily result in a similar fauna, and conversely. 
For example, there is considerable uniformity in the 
fauna of South America throughout its length and 
breadth, even though we find there every variety of 
physical conditions, from the cold deserts of the high 
Andes to the luxuriance of the Brazilian forest, or from 
the burning deserts of Chile to the grassy plains of the 
Argentine. On the other hand, there is very little 
resemblance between the animals of the grassy plains 
of South America and those of Africa, despite the 
similarity in physical conditions. The second point 
which struck him was that the resemblances or differ- 
ences between the faunas of two areas are directly 



10 INTRODUCTION 

proportioned to the nature of the barrier which sepa- 
rates the two regions. Transverse mountain chains, 
such as the Himalayas or Atlas, separate two different 
faunas. Similarly, lands separated by a broad and 
deep belt of ocean may have quite different faunas ; 
those separated by a shallow and narrow strait may 
have almost identical animals. Such facts led him to 
believe that each species originated in a particular 
region, and spread out from that region till it was 
stopped by some barrier to further distribution. The 
remarkable features of the animals of isolated regions 
can be explained on this hypothesis as the result of 
descent with modification from the original forms. 

One result of the direction thus given to the study of 
distribution has been to make the division of the globe 
into zoogeographical regions, and the study of the faunas 
of the different regions, of supreme importance, and it 
is this aspect which is studied in most books on the 
subject. But, obviously, another and more truly 
geographical point of view is possible. We may study 
the animals of the natural regions of the globe as form- 
ing a part of the features of those regions, and in this 
case attention is directed rather to the adaptations 
displayed by the animals, than to their zoological 
relationships. 

In deliminating the natural regions of the globe the 
botanists have played a large part, for they have shown 
that the existence of the great plant associations 
depends upon the climate, the relief, and so forth of 
the region. To the practised eye a collection of plants 
from e. g. the Mediterranean region gives a great deal 
of information in regard to the region. For example, 
the small silvery leaves of such plants, and the other 
devices for husbanding water, together with the occur- 



NATURAL REGIONS OF THE GLOBE 11 

rence of many bulbous plants, speaks to a climate where 
dry and wet seasons alternate, and so on. The depen- 
dence of the more active animal upon its surroundings is 
less intimate than that of the passive plant, but even 
here the characters of the animals of a region tell us 
something of the physical features of that region. That 
we find in Brazil, for example, animals so thoroughly 
adapted to the arboreal life as sloths, marmosets, 
monkeys, and so forth, suggests at once that dense 
forest occurs in the region. That Africa has an 
enormous number of antelopes — enormous both as 
regards species and individuals — suggests the existence 
in that continent of open plains, and so with other 
regions. 

The botanists recognize three great plant formations, 
which roughly divide the surface of the land among 
them. These are woodland, grassland, and desert. 
Such a simple division would help us little in the case 
of animals, but as all animals depend ultimately for 
their food upon plants, a modification of this classi- 
fication may serve as a framework in the study of 
animal distribution. There is, for example, a consider- 
able difference in the life conditions of animals which 
live in regions where the winter cold periodically checks 
plant growth, as compared with those where no such 
temperature check occurs. This gives us a first dis- 
tinction between the animals of cold or temperate 
regions and those of tropical regions. In both of these 
forest, grassland, and desert occur, but it is possible to 
pick out certain well-defined types in order to study 
their faunas separately. Thus, among the various forms 
of temperate forest, the Taiga or coniferous forest of 
Asia and North America has a well-defined assemblage 
of animals showing some interesting adaptations. 



12 INTRODUCTION 

Again, both in Asia and in North America we have 
vast areas of natural grassland forming well-defined 
Steppe areas, which possess a characteristic fauna. The 
great mountain chains of the earth's surface are peopled 
by faunas having certain special features, and the vast 
area of coast-line which fringes the Arctic sea forms 
a cold desert or tundra, whose fauna has many pecu- 
liar features. As natural regions with a cold winter 
climate then, we have to consider (1) the Tundra, 
(2) the Taiga or coniferous forest, (3) the Steppe, best 
developed in the northern hemisphere, and (4) Mountain 
regions. 

Where the temperature is permanently high, and 
the precipitation great, we have (5) luxuriant Tropical 
Forest, with its characteristic fauna, differing according 
as the forest occurs in Africa, Asia, or South America, 
but showing in all cases certain special adaptations. 
Again, in warm or tropical regions where the tempera- 
ture is still high, but the rainfall small and unequally 
distributed throughout the year, we have a thinning of 
the forest into that type of grassland, or grassland 
mingled with wood, which the botanists call Savana. 
As the rainfall diminishes the savana thins out into 
desert, so that we may conveniently consider (6) 
Savanas and Warm Deserts together. 

This still leaves to be considered the fauna of (7) 
Islands, which show some special features, and also the 
animals of aquatic habitat, which we must consider 
separately, according as they live (8) in the sea, or 
(9) in fresh water. 

Such a scheme is obviously incomplete, in that it 
does not cover the whole surface of the globe. It 
omits, for example, any consideration of the fauna of 
the deciduous forest which covers so much ground in 



NATURAL REGIONS OF THE GLOBE 13 

Europe and North America, and of the animals of the 
Mediterranean or scrub forest, found round the Mediter- 
ranean Sea, in California, and elsewhere. We shall find, 
however, that such regions have for the most part 
a transitional fauna, made up of units from the sur- 
rounding regions, and that further they have been 
much altered by man's interference. It is true that the 
effects of this interference are often interesting, for 
while some animals die out as civilization spreads, 
others, like the rats, the common sparrow, the cock- 
roaches, some parasites, and so on, adjust themselves 
to the altered conditions, and prosper under civiliza- 
tion as they never did in former days. But a considera- 
tion of these points would take us too far from our 
immediate subject. We shall therefore confine our- 
selves to a consideration of the nine natural regions 
already given, and fill up whatever gaps this method 
may leave by a final consideration of the zoogeogra- 
phical regions into which zoologists have divided the 
globe. But as the greater part of this book is thus 
devoted to the geographical aspect of animal distribu- 
tion, a word or two may be added in further explanation 
of the difference between the two points of view, the 
zoological and the geographical. 

To the zoologist it is a fact of great interest 
that the sloths, ant-eaters, and armadillos should 
occur in South America, and nowhere else. But the 
geographer is more interested in the fact that the sloth 
is a purely arboreal animal, fitted only for life in the 
dense forest, while the armadillo, for example, shows 
adaptations to quite other habitats. The difference 
between the sloth of the Amazon forest and the squirrel 
of the Siberian taiga, again, means something very 
different to zoologist and geographer, for the latter 



14 INTRODUCTION 

sees in it a reflection of the difference between the 
two forests, which interests the other less, and only 
incidentally. 

References. A realization of the connexion between the study of 
the facts of animal distribution and the general theory of evolution may 
best be obtained from Darwin's Origin of Species and Wallace's Dar- 
winism. Wallace's classical work on Geographical Distribution (two vols., 
London, 1876) should also be consulted. An interesting discussion of 
the purely geographical standpoint will be found in the chapters on 
animal geography in de Martonne's Traite de Geographic Physique (Paris, 
1909), which gives copious references. 



CHAPTER I 

THE TUNDRA AND ITS FAUNA 

One of the well-marked natural regions of the world 
is the Tundra, that treeless area which fringes the 
margin of the far northern seas, and is characterized 
by its climate, its plants and animals, and to some 
extent also by its topography. Originally applied only 
to the treeless lands of Northern Asia, lying to the 
north of the forest or taiga, the term is now by exten- 
sion given to all areas of similar character, occurring 
alike in the Old and New Worlds. In the southern 
hemisphere the tapering of the land-masses, and their 
cessation in relatively low latitudes, make the develop- 
ment of true tundra impossible. It is true that con- 
siderable land-masses occur within the Antarctic area, in 
latitudes lower than those in which the northern tundra 
finds its limit, but the climate and the absence of a direct 
connexion between these areas and the continents have 
prevented the development of the characteristic tundra 
plants and animals. In the Antarctic land-mass flower- 
ing plants are, with two exceptions, absent, and mosses 
and lichens are only slightly developed. Associated 
with this we have a complete absence of land mammals 
— a very striking difference from the northern tundra. 

The boundaries of the tundra are well marked. As 
already indicated, on the continents the southern 
boundary is the beginning of the forest zone. This 
limit is, roughly speaking, marked out by the July 
isotherm of 50°. Wherever the mean temperature of 
the hottest month exceeds 50° F., there the tundra 



16 THE TUNDRA AND ITS FAUNA 

dies away into forest. The result is that the continental 
tundra forms a band of very varying width. The mild- 
ness of the Western European climate pushes the tree 
limit up within the Arctic Circle, and reduces the tundra 
zone to a narrow band to the north of Scandinavia. 
Thence it extends through European Russia into 
Siberia, and reappears again at the other side of the 
Bering Strait to extend across Arctic America. Here 
to the east it revenges itself for its conquest by the 
forest in Western Europe by pushing the forest zone 
far to the south, so that a band of tundra extends 
down the coast-line of Labrador, and even into New- 
foundland. 

The northern limit of the continental tundra is the 
polar sea, but the tundra type reappears on the margin 
of the land-masses lying within that sea. The islands 
of the American archipelago, Baffin Land, Greenland, 
the northern shore of Iceland, Spitsbergen, Franz 
Josef Land, Nova Zembla, the New Siberian Islands, 
&c., are all fringed by a band of tundra. Its northern 
extension may indeed be gathered from the fact that 
the reindeer, one of the most characteristic tundra 
animals, was hunted by the Sverdrup expedition in 
King Oscar Land, which extends to about 80° 30' 
N. lat. In these regions the sea again forms one of the 
boundaries of the tundra zone. The other boundary is 
formed by the presence of eternal ice and snow. Gener- 
ally it may be said that tundra occurs wherever the 
meltmg of the snow is sufficient to expose a surface 
upon which land plants may grow. 

The climate throughout this great area naturally 
varies, but the special features are the following. 
Nowhere does the mean temperature of the warmest 
month exceed 50° F., and it is often much below this. 



THE TUNDRA AND ITS FAUNA 17 

The precipitation is everywhere small, except in the 
south-western extremity of Greenland. Elsewhere the 
mean never exceeds 10" per annum, and may be much 
less. The winters especially are remarkable for the 
clearness and dryness of the atmosphere and the 
virtual absence of precipitation. The result is that, 
contrary to what might be expected, the snow does not 
form everywhere a thick mantle, and the frequency of 
strong winds helps to diminish its thickness in places, 
a fact which greatly aids the obtaining of food by 
such herbivorous mammals as the reindeer and musk- 
ox'. During the short summer precipitation is frequent, 
though slight, and fog and mist are common. The sub- 
soil is permanently frozen, and there is thus no ground 
water. This renders all erosion mechanical, and as 
springs are absent the rivers are fed only by the melt- 
ing of ice and snow, and are temporary, being frost- 
bound in winter. 

There are only two seasons — winter and summer — 
and the winter extends far into the months which are 
spring elsewhere, so that March or even April may be 
the coldest month. It is apparently these months which 
take the largest toll of animal life, for Nordenskiold 
notes that the reindeer are in better condition in the 
depth of winter than in the spring months. Summer 
comes with extraordinary rapidity, and with its coming 
life suddenly bursts into activity. Thus all the flowers 
bloom at once, giving rise to the local luxuriance 
noticed by many explorers. The rapidity of develop- 
ment is of course aided by the virtually continuous 
daylight. As the rays of sunlight have a very oblique 
direction, local conditions count for much in promoting 
the growth of plants, and therefore the occurrence of 
land animals. Thus a slope where the ice-cold water 

1404 B 



18 THE TUNDRA AND ITS FAUNA 

drains away as the snow melts is favourable to plant 
growth, while level ground is very unfavourable. A 
sunny exposure also exerts much influence. The Sver- 
drup expedition noted that the Arctic hare is prac- 
tically limited to the regions where large valleys open 
out into fiords, for only here is vegetation abundant 
enough to supply its needs. 

As regards topography one must note that the tundra, 
like the semi-arid lands of other latitudes, is charac- 
terized by a very youthful condition of drainage. As 
already stated, the rivers are temporary, chemical 
erosion does not occur, and therefore the process of 
carving up the land into hill and valley goes on very 
slowly, and the land is imperfectly drained. The 
imperfect drainage is aided by the fact that the ex- 
treme coldness of the soil is unfavourable to bacterial 
life, and thus humus accumulates and favours the 
growth of bog mosses as contrasted with higher plants. 
These hold up the water like a sponge, and so hinder 
drainage. When Nansen and his party left the inland 
ice of Greenland they descended to a little tarn, whose 
water drained by a stream to the distant fiord. In 
their descent, as the leader notices, they found that the 
main streams had often transverse tributaries, which 
greatly hindered progress. The picture may be taken 
as characteristic of the tundra. Lakes fed by melting 
ice, streams showing a very undeveloped drainage 
system — these are characteristic features, which, aided 
by the climate, account for the very local development 
of a covering of vegetation, and therefore for the 
curiously local appearance of animals. 

Without discussing the plants of the tundra in detail 
we may note those points which are of special impor- 
tance for animal life. The first of these is the great 



THE TUNDRA AND ITS FAUNA 



19 



abundance of mosses and lichens, which do not die 
down in winter, and are therefore permanently avail- 
able as pasture for the herbivorous mammals. It is 
well known that the lichen popularly called reindeer 
moss (Cladonia rangiferina) , which occurs over wide 
areas, forms a very important part of the winter food 




Fig. 1. The Tundra in Northern Russia, summer conditions. The 
illustration shows the undifferentiated nature of the drainage, and 
shows also that at this season pasturage is freely available for 
herbivorous mammals. 

of the reindeer. Other areas are clad in hair moss 
(Polytrichum), or bog moss (Sphagnum). Among the 
higher plants we may note the presence of dwarf 
willows, birches, alders, &c., whose branches stick up 
through the snow, and whose buds and seeds are of 
great importance as part of the food of the ptarmigan 
and the snow-bunting. In the more favourably situated 
regions berry-bearing shrubs occur, such as crowberries, 

B 2 



20 THE TUNDRA AND ITS FAUNA 

whortleberries, &c., again forming an important part of 
the available food supply. Again, as in the case of the 
Swiss alps (p. 74), the vegetative growth of the plants 
Is checked by the natural conditions, and thus, though 
stunted in appearance, they are relatively rich in 
proteids and fats, and relatively poor in cellulose, which 
makes their nutritive value high. With all that can 
be said, however, the land offers but little food, and 
the vast majority of the tundra animals depend partly 
or wholly upon the sea, and are therefore necessarily 
confined in their distribution to the margin of the sea. 
The German expedition to Greenland made large 
collections of both birds and mammals, and observed 
the habits of all as closely as possible, and the conclu- 
sion arrived at is that only four of the mammals can 
be said to be permanently dependent upon the land 
for food ; these four being the reindeer, the musk-ox, 
the Arctic hare, and the lemming. Of the many birds 
known to visit Greenland, only two can be said to be 
at once permanent residents and wholly dependent 
upon the land for food. These are the redpoll {Linota 
hornemanni) and the ptarmigan {Lagopus hyperboreus). 
All other birds and mammals are either partially 
migratory or depend to some extent at least upon the 
harvest of the sea. Even of the land plants the last 
statement is partly true, for it is said that the phanero- 
gams are especially abundant about the breeding-places 
of the sea birds, on ground enriched by their droppings, 
and such birds feed in the sea. Again, even of the four 
mammals named, the reindeer, according to Norden- 
skiold, does not disdain seaweed in times of scarcity. 
Everywhere over the globe animals depend ultimately 
upon plants, which alone can fix inorganic matter 
in organic form, but it may be said to be the special 



THE TUNDRA AND ITS FAUNA 21 

character of the tundra animals, like the fewer animals 
of the Antarctic area, that it is marine plants, rather 
than terrestrial ones, which form the basis of their 
food supply. 

Having thus summarized the conditions of life in the 
tundra we may give some account of the fauna, begin- 
ning with the ungulates among mammals. The rein- 
deer {Eangifer tarandus) is widely spread throughout 
the region, though nowhere very abundant as indi- 
viduals. On the continent of America there is a marked 
distinction between those forms which haunt the forests, 
the so-called woodland caribou, and the smaller forms, 
with larger antlers, which occur in the tundra. The 
latter, the barren-ground forms, seem to migrate south- 
wards towards the forest in winter, but this is impossible 
with the herds which occur in the Arctic islands. In 
King Oscar Land and the adjacent regions the Sverdrup 
expedition found the animal widely distributed but not 
abundant, apparently on account of persecution by the 
Arctic wolf. The absence of this animal in Spits- 
bergen perhaps accounts for the greater abundance of 
the reindeer there. It occurs also in the suitable parts 
of Greenland, where the wolf is again absent. On the 
continent of Asia the reindeer occurs in summer in 
suitable localities in the tundra region, but here also it 
seems migratory, and thus not wholly dependent upon 
the tundra for food. 

The musk-ox {Ovihos moschatus), the second large 
herbivore of polar regions, has a much more limited 
distribution. Found fossil in Europe and Asia, it is 
now limited to the American side of Arctic regions. 
On the continent of America its eastward distribution 
is limited by the Mackenzie River, but it is apparently 
abundant in the northern parts of Greenland, in 



22 THE TUNDRA AND ITS FAUNA 

Grinnell Land, and in the adjacent regions. It is 
non-migratory, finding food throughout the year by 
scraping away the thin covering of snow. A markedly 
social animal, the herds seem capable of defending 
themselves against the Arctic wolf, which attacks 
chiefly young stragglers. 

To this short list we should perhaps add the fact that 
the mammoth occurs in the tundra in the subfossil 
condition in Asia and also in Alaska. 

Rodents are represented in the tundra by the Arctic 
hare {Lepus glacialis), which is very abundant in suit- 
able localities. Even in winter it finds food enough in 
the grasses which project through the snow. Its 
greatest enemy is the wolf, which seems to feed largely 
upon it, but in spite of the abundance of that animal 
in King Oscar Land the Arctic hare is stated to be very 
abundant there. Another important rodent of the 
tundra is the lemming {My odes torquatus), which is 
sometimes extraordinarily abundant. Absent from 
Spitsbergen, it occurs elsewhere on both sides of the 
Arctic region. Perhaps because of the paucity of 
vegetation in its natural habitat, this northern lemming 
does not show the enormous fertility of the Norwegian 
form, nor does it seem to migrate in the same fashion. 
In some regions, as in Nova Zembla, it is, however, 
remarkably abundant. While the other herbivorous 
animals named find their food in ^vinter either by 
scraping away the snow, or by nibbling the protruding 
shoots, the lemming, a much smaller animal — it is not 
much bigger than a mouse — lives in winter beneath the 
snow, making runs and burrows in the underlying 
ground. MTien the snow melts in spring these runs 
appear, ramifying over the surface in all directions. 
The Norwegian lemming {M. lemmus) is also circum- 



THE TUNDRA AND ITS FAUNA 23 

polar, but does not extend so far to the north as the 
other species. 

In the tundra, as elsewhere, the presence of large 
herbivores naturally attracts their enemies the large 
carnivores, necessarily fewer in number, and usually of 
greater intelligence. As masterful and highly organized 
animals the large carnivores do not as a rule show 
a very close adaptation to one type of country only, 
nor are they, as a rule, like such herbivorous animals 
as the musk-ox, driven by stress of competition to the 
unfavourable parts of the surface. The carnivores 
which occur in the tundra, therefore, do not as a rule 
form an integral part of its fauna ; rather are they 
intruders from other regions. Thus the wolf {Canis 
lupus), absent in Greenland, in Spitsbergen, &c., occurs 
in Arctic Asia and Arctic America, and extends also 
into such regions as Grinnell Land and King Oscar 
Land. Its near ally, the Eskimo dog, is a very impor- 
tant animal in Greenland and elsewhere. Very in- 
sufficiently fed by its master, the catholicity of its 
appetite may be gathered from the fact that it will eat 
fish, shell-fish, seaweed, and refuse. 

Much more truly Arctic than the wolf is the Arctic 
fox {Canis lagopus), widely distributed in the polar 
regions of both the Old and New Worlds. Its food con- 
sists of birds, especially the ptarmigan, but it is con- 
strained to add to this refuse and even seaweed. 
Lemmings are also an important part of its diet where 
they occur, and by some it is believed to store the 
bodies of these for the winter, when it is often hard- 
pressed. Two other land carnivores occur in the tundra, 
but both are immigrants from their natural home 
further south. These are the ermine {Mustela erminea), 
which follows the lemming to the coasts of the Arctic 



24 THE TUNDRA AND ITS FAUNA 

sea, and the glutton {Gulo luscus), a forest mammal, 
which just reaches the tundra. 

Among the mammals which find their food in the sea, 
Ave must place the polar bear. As its name ( Ursus mari- 
timus) indicates, this animal haunts the margin of the 
sea, where it is found among the drift and floe ice, on 
the look out for its natural prey, seals and the walrus. 
It is thus not in any true sense a tundra animal, al- 
though occurring round the margin of the tundra region 
throughout its extension. Of the many kinds of seals 
also, we can only say here that though they breed on 
the shore they are not in any sense tundra animals. 

We may pass next to the birds of the tundra. In 
regard to these it is noticeable that large numbers of 
migrants occur, especially sea birds and those which 
haunt the vicinity of the shore or of fresh water. 
These come north to breed in the relative security of 
the tundra, and also probably because they find the 
long northern daylight an advantage, for it lengthens 
the period during which the search for food can be 
carried on. As winter approaches, these birds travel 
southwards, fleeing from the increasing cold and dark- 
ness. It is unnecessary to give lists of these migratory 
forms. All travellers to tundra regions, whether to the 
mainland areas or to the lands of the polar sea, speak 
of many kinds of gulls, 'of skuas, of kittiwakes, of 
geese, of various forms of ducks, including the eider, of 
auks and guillemots, of sandpipers, terns, petrels, and 
so forth, none of which can be regarded as definitely 
characteristic of the tundra, though their summer 
abundance at certain special localities is one of the 
features of the region. It is, otherwise with the true 
land birds, which, though relatively few in number, 
help to give its characteristic facies to the region. First 



THE TUNDRA AND ITS FAUNA 



25 



among these we must place the ptarmigan (Lagopus), 
of which more than one species occur in the tundra. 
In Greenland, in Arctic America and the adjacent 




Fig. 2. The Ptarmigan, with nest, young, and eggs, showing the 
stony uplands where the bird breeds in Highland Scotland. {From 
a apecimen in the Royal Scottish Museum.) 



regions, in Spitsbergen, in Northern Asia, these birds 
occur, sometimes in considerable numbers. In the slow 



26 THE TUNDRA AND ITS FAUNA 

agony of the last march of de Long and his companions 
after the wreck of the Jeannette, it was by the help of 
the ptarmigan and reindeer shot that the final cata- 
strophe was postponed so long. After Nansen and his 
companions arrived in safety at the east coast of 
Greenland, their crossing of the inland ice completed, 
they whiled away their months of waiting for a ship by 
the help of ptarmigan shooting. Sverdrup and his 
companions shot many for food during their Arctic 
expedition, and similarly almost every expedition which 
has landed in tundra regions has noted the presence 
and characters of the birds. 

The ptarmigan share with the Arctic fox, the stoat 
or ermine, and not a few other northern forms the 
peculiarity of displaying a seasonal change of colour. 
This change doubtless aids these varied animals in 
escaping from their enemies, or in stealing unperceived 
upon their prey. Like many other tundra animals also, 
the ptarmigan is social, being found in flocks, except 
at the pairing season. This is no doubt associated with 
the fact that food is only obtainable in certain areas, 
separated by extensive barren regions. Though in most 
favourable tundra regions ptarmigan are to be found 
throughout the year, a certain amount of migration 
occurs. Thus in Greenland they are commoner in the 
south in winter than in summer. Needless to say, 
ptarmigan are not peculiar to the tundra, for they 
extend far to the south of the region. 

The only songster of the tundra is the snow-bunting 
{Plectrophenax nivalis), which is very widely distributed, 
and is spoken of by most explorers, who welcome its 
twittering song in spring. There is no doubt that it is 
largely a migrant, nesting in the north, and turning 
southwards in the autumn. Occasionally, however, 



THE TUNDRA AND ITS FAUNA 27 

it appears to winter in the Arctic, notably in Green- 
land. 

Wherever in the tundra region lemmings and small 
birds are to be found, there occurs the snowy owl 
{Nyctea nivea), though it does not seem to be common 
except where lemmings are abundant, as in Nova 
Zembla and parts of the mainland of Northern Asia, 
The bird has a general resemblance in coloration to 
a ptarmigan in winter plumage, and often lives in the 
stony regions frequented by that bird, upon which the 
owl preys. It is, however, no exception to the rule that 
the carnivorous animals of these barren regions need to 
lay the sea under contribution as well as the land, for it 
eats fish in addition to birds and small mammals. It 
winters in the tundra, and is a very characteristic bird 
of the region. Another predatory bird of the Arctic is 
the Greenland gerfalcon (Falco candicans), a beautiful 
bird, predominantly white in colour, which inhabits 
Greenland and Arctic America, and is represented by 
an at least closely allied species in Northern Asia. It 
preys upon ptarmigan and other birds, and also upon 
lemmings, and winters in Greenland. The third pre- 
daceous bird of the tundra is the raven {Corvus corax), 
which is the scavenger of the region, and will eat 
practically anything from land or sea. 

As is to be expected from the unfavourable con- 
ditions of life, reptiles and amphibians are absent, and 
fresh-water fish are not abundant. Representatives of 
the salmon family occur in some lakes, but there is 
nothing characteristic. 

Among the invertebrates the insects present some 
interesting points. Except in Spitsbergen and Nova 
Zembla, mosquitoes are enormously numerous, and 
form in many regions a terrible plague. It may seem 



28 THE TUNDRA AND ITS FAUNA 

curious that they should be abundant in this cold 
region, but the cause is to be looked for in the un- 
developed condition of the drainage system, already 
mentioned. The absence of any run-off in winter gives 
the tundra, as we have noted, the characters of a semi- 
arid region, with the result that the water formed in 
summer by the melting of the snow tends to accumu- 
late in innumerable lakes and pools. In these the 
mosquito larvae swarm, and the natural checks, e.g. in 
the shape of small fish who feed on the larvae, must be 
insignificant. From the pupal stage the adults emerge 
towards the middle of June, and they are then extra- 
ordinarily abundant till the middle of August, when 
they disappear, after having laid their eggs in the pools. 
These pools freeze or dry up with the onset of winter, 
but the eggs or larvae remain uninjured, to hatch or 
recommence active life with the coming of water in the 
spring. It is possible that the life-history is lengthened 
by the cold, but the rapidity of reproduction is certainly 
not checked, except in the coldest regions. In addition to 
mosquitoes a considerable number of other flies occur, 
especially about the houses of the Eskimo, &c., breeding 
in the refuse thrown out. Indeed, flies predominate 
among northern insects, the percentage increasing as 
we pass northwards. The reason lies apparently in 
the fact that the larval stage is usually short, and 
can be run through in the brief period of warmth. 

With the exception of the curious parasites known as 
Strepsiptera, all the other orders of insects are repre- 
sented, the bees and butterflies fulfilling here their 
usual role as fertilizers of flowers. The very short 
active period of vegetation has a curious effect upon 
the development of plant-eating insects. As is weU 
known, in more temperate countries butterflies usually 



THE TUNDRA AND ITS FAUNA 29 

lay their eggs in the autumn (except in the case where 
there are two annual broods), and these eggs pass the 
winter as eggs, or, if the larvae hatch, they winter in 
a very undeveloped state. In the spring, activity is 
early resumed, and the life-history is rapidly passed 
through, so that the butterflies appear in summer. In 
Greenland, butterflies do not appear till the middle of 
July. If they lay their eggs, and these hatch at once, 
the resulting larvae have, in the colder parts, only some 
five weeks before winter sets in. Activity does not 
recommence till at earliest the first week of the follow- 
ing June, and as it cannot be supposed that the animals 
can pass through larval and pupal life before the onset 
of cold, they must pass a second winter in the larval 
state, the butterfly emerging in the following July to 
lay its eggs and die. This great lengthening of the life- 
history cannot be ascribed wholly to the cold ; we must 
suppose that it is also due to the fact that caterpillars 
must necessarily wait in spring until their food plants 
have made some new growth. This life-history, there- 
fore, again emphasizes the baneful effect on animal life 
of the scanty development and slow growth in spring of 
the plants of the tundra. 

In addition to insects, a few earthworms occur in the 
warmer parts, and there are a few land and fresh-water 
shell-fish and some spiders and mites. In general, how- 
ever, it may be said that among the invertebrates the 
insects are the most conspicuous and numerous forms. 

As a pendant to this picture of life on the tundra 
we may add a brief consideration of the animals of the 
shore, which, as we have noticed, have considerable 
direct and indirect importance for the land animals. 
Man in these regions is practically dependent upon the 
sea for food, for fuel, and for clothing, for the land 



30 THE TUNDRA AND ITS FAUNA 

gives him almost nothing. It is a commonplace of 
physiology that in cold climates his need of fat is great, 
but in this respect he resembles all the other animals 
of the region, all of whom seek fatty food, and store 
up in their bodies reserves of this heat-producing sub- 
stance. The food from which the larger marine animals 
obtain their supplies of fat is almost always, directly or 
indirectly, found in the myriads of small Crustacea which 
haunt polar seas, and whose bodies contain much oil. 
Arctic seas are indeed specially characterized by their 
wealth of small Crustacea and of marine mammals, and 
the two facts are closely connected. The Crustacea feed 
the fish of the polar seas, which, though of relatively 
few species, are often extraordinarily abundant as 
individuals. The seals and toothed whales feed upon 
fish. Small Crustacea are also devoured by molluscs, 
of which the mud-haunting forms are devoured by the 
walrus, and the floating forms by the whalebone whales, 
so that the Crustacea form the basis of the marine food- 
supply. They are in their turn fed by the more minute 
forms of life, especially by the minute plants, such as 
the diatoms, so abundant in polar seas. 

The few survivors of the ill-fated Greely expedition 
kept themselves alive by the collection of ' shrimps ' 
in the shore-water. These ' shrimps ' must have been 
largely the small crustaceans caUed amphipods, which 
are enormously abundant in polar seas, and the fact 
that they were so utilized may be taken as emblematic 
of Arctic conditions. 

Apart from Crustacea, the littoral fauna of the Arctic 
is fairly rich. A considerable number of large molluscs 
occur, including in the ' gapers ' Mya and Saxicava 
mussel-like forms, which constitute an important part 
of the food of the walrus. Where molluscs abound, 



THE TUNDRA AND ITS FAUNA 31 

starfish, which prey upon tliem, are also abundant, and 
reach a large size. Where seaweed is abundant, sea- 
urchins occur ; according to Nordenskiold, west of Nova 
Zembla they are so numerous as almost to cover the 
bottom. The mud holds a considerable number of 
marine worms, and other less striking invertebrates 
also occur in numbers. Here, however, we must note 
that if the sea contributes a wealth of food to land 
animals, yet the land also gives something to the sea. 
The icebergs which detach themselves from the glaciers 
carry much rock-waste to the sea, and this forms a fine 
mud very favourable to animal life, for very many 
shore animals are mud-eaters. The ice-foot and drift- 
ice also contribute to the rock debris spread over the 
bottom, and the proximity of the glaciers to the shore 
in many places must mean that the rock-waste is 
carried by the turbid streams of summer direct to the 
ocean, instead of being spread over the land, as is for 
instance so much of the glacial mud of the Alps. In 
other words, the mud which in Central Europe forms 
such vast fertile areas as the Plain of Lombardy, is in 
Arctic regions carried seawards to help to feed the 
swarming life of the sea. It is this fact which explains 
the wealth of the Arctic in marine birds and mammals, 
and its poverty in land forms of either. The poverty 
of the land is made up for by the wealth of the sea. 

The characteristic marine mammals of the extreme 
north are the walrus and the earless seals, all of which 
spend a considerable part of their life on shore, espe- 
cially at the breeding season, and the whales, toothed 
and whalebone, which never voluntarily come on shore 
at all. All have, of course, had terrestrial ancestors, 
and we may see one justification of the evolution of 
their adaptations to a marine habitat in the fact just 



32 THE TUNDRA AND ITS FAUNA 

emphasized — the poverty of the land and the relative 
wealth of the sea in these northern latitudes. Another 
cause of the abundance of the seals and their allies in 
Arctic and Antarctic waters is certainly to be sought 
in the fact that these animals must come on shore to 
breed, and suitable regions for this purpose, offering 
security against attack, except in the case of man, the 
great enemy of the large mammals, are to be found in 
the frigid rather than in the temperate or torrid zones. 

Of the Arctic seal-like animals, the walrus {Trichechus 
rosmarus), which is circumpolar, is one of the most 
interesting forms. As already noted, it is stated to 
feed chiefly upon molluscs, but apparently adds fish, 
swimming birds, and even seals to these. It seems to 
pass a considerable part of its life on shore, or at least 
on floating ice-floes. The massive tusks are used in 
digging up mussels from the mud, and also in helping 
the animal to clamber upon the ice. 

The true seals are represented by a number of species, 
five or six occurring in Greenland. The presence of 
a number of nearly related forms within a limited area 
means a very perfect adaptation to the natural con- 
ditions. Analogous conditions are presented by the 
many kinds of antelope which are found in the open 
plains of Africa, and the many kinds of deer in the 
forests of Asia. 

The true seals are very clumsy on land, but are very 
perfectly adapted for swift movement in the sea. They 
feed upon fish, to which at times they add shell-fish and 
crustaceans. In the sea their great enemy is the killer 
whale, but their enemies on land are much more serious, 
consisting of the polar bear and man, both of whom 
take advantage of the animal's relative helplessness on 
land, and the fact that they must come on shore to 



THE TUNDRA AND ITS FAUNA 33 

breed, and that the young must spend the first two or 
three weeks of their life on shore. Many of the seals 
are markedly migratory, going south in winter to avoid 
the intense cold of the north. This is especially true of 
the Greenland seal {Phoca groenlandica) , which seems 
incapable of making a breathing -hole in the ice, and 
therefore must have relatively open water in its haunts. 
On the other hand, the ringed seal [Phoca hispida), 
which does make such breathing-holes, is almost non- 
migratory, living permanently in the coldest regions. 
These two species will thus not compete with each 
other, and all the species doubtless show similar 
minor adaptations, which fit them for different parts 
of the common environment ; but it is not always 
possible to explain wherein these special adaptations 
consist. The large bearded seal {Phoca harbata) is 
another form which makes breathing-holes. The very 
curious crested seal (Cystophora cristata) is not only 
migratory but also pelagic in its habits, avoiding the 
neighbourhood of land, and bringing forth its young 
on ice-floes. It is a bold species, apparently a swift 
swimmer, and eats cuttles as well as fish. The common 
seal {Phoca vitulina) also occurs in Arctic waters. 

The cetaceans of the north are numerous, and in- 
clude some very large animals. Thus among the whale- 
bone forms we have the Greenland whale {Balaena 
mysticetus), with its enormous head, and its elaborate 
series of baleen plates, which filter the minute crus- 
taceans and molluscs upon which it feeds from the 
sea water. The huge rorquals (Balaenoptera), though 
found in practically all seas, often seek the vicinity of 
northern coast-lines in spring for breeding purposes. 
Among the toothed whales the narwhal {Monodon 
monoceros) is a true northern form, and lives largely 

1404 c 



34 THE TUNDRA AND ITS FAUNA 

upon cuttles and crustaceans. The white whale {Delphin- 
apterus leucas) is similarly an Arctic form, remarkable 
for its habit of ascending rivers for a considerable 
distance. The killer whale {Orca gladiator), on the 
other hand, which is a very widely distributed animal, 
chiefly occurs in the Arctic in summer. 

If we sum up the facts in regard to the distribution 
of tundra animals, and of the marine forms which 
occur round its seaward margin, we may say briefly 
that the tundra fauna is virtually uniform throughout. 
The animals, generally speaking, are either circumpolar 
at the present time, or have once been circumpolar, 
and there is no distinction between eastern and western 
faunas. In other words, the fact that the ' salt, estrang- 
ing sea ' is here more or less ice-bound makes the land 
areas virtually continuous, and this, combined with the 
marked uniformity of physical conditions, leads to 
practical uniformity of distribution, both of plants and 
of animals. No such similar uniformity exists in regard 
to the other natural regions of the world. Though the 
steppes of Asia show a general resemblance in physical 
conditions to the steppe-like regions of North America, 
yet their faunas are different. In the same way, the 
faunas of the similar equatorial forests of South America 
and Africa are markedly dissimilar, and there is almost 
no resemblance between the desert fauna of Australia 
and those of Africa or of America. No resemblance, 
that is, when the actual affinities of the animals are 
considered, but necessarily desert animals or forest 
animals, whatever their affinities, share certain adapta- 
tions to forest or desert life. 

References. Accounts of tundra animals are to be found in almost 
all books dealing with the Arctic regions. The following may be men- 
tioned as giving a considerable amount of detail : Manual of the Natural 



THE TUNDRA AND ITS FAUNA 35 

History, Geology, and Physics of Greenland and the Neighbouring Regions, 
edited by Professor T. Rupert Jones (London, 1875) ; The Voyage of the 
Vega, by A. E. Nordenskiold (English Translation, London, 1881) ; 
Gronland-Expedition der Gesellschaft fur Erdkunde zu Berlin, unter 
Leitung von Erich von Drygalski (Berlin, 1897). The second volume of 
the last named gives a very full account of the fauna and flora of Green- 
land by Dr. Ernst VanhofEen. The animals of polar regions generally 
are discussed in Dr. Bruce's Polar Exploration (London, 1911). In 
addition the accounts of their explorations published by Nansen, Sver- 
drup, the Duke of Orleans, the books dealing with the Jeannette ex- 
pedition, &c,, may be consulted. Kobelt's Die Verbreitung der Tierwelt 
(Gemassigte Zone), published at Leipzig in 1902, discusses tundra 
animals in general, and gives some characteristic views of tundra life. 
See also Seebohm's Siberia in Asia (1882), and the same author's Address 
to Sectibn E (Geography) at the Nottingham Meeting of the British 
Association, 1893. 



C 2 



CHAPTER II 

THE TAIGA, OR CONIFEROUS FOREST, AND 
ITS FAUNA 

Strikixgly different from the fauna of the tundra 
is that of the temperate forest, which forms a wide 
belt in the northern hemisphere, lying just south of 
the tundra. Here the climate is more favourable, 
especially in the southern portion, and the flora far 
more luxuriant. Nevertheless here, as in the tundra, 
the ebb and flow of plant life is caused by the seasons, 
that is, by the varying amounts of heat received. In 
subtropical countries, with their winter rainfall, it is 
water, not heat, which determines vegetative activity. 
In the tropics, except where there is a well-marked dry 
season, vegetative life is practically continuous, but in 
the temperate forest zone, no less than in the drier 
steppes, it is the alternation of summer and \^'inter 
which is of importance. As all animal hfe in these 
regions ultimately depends upon land plants, this means 
that there are periodic alternations of plenty and 
scarcity. In the forest zone, however, this is less 
marked than in the steppe zone. In the coniferous 
forests the trees for the most part keep their leaves all 
the year round. However deep the snow, the twigs 
and branches of the trees are exposed, and these twigs 
and branches very often carry nuts, berries, or seeds, 
which persist throughout the winter, and thus prolong 
the summer abundance into the time of scarcity. 
Further, the forest gives shelter, and thus diminishes 



THE TAIGA AND ITS FAUNA 37 

the rigour of the winter climate. The thick branches 
may shelter the ground from snow, the covering of 
dead leaves may protect it from frost ; hollow trees 
and dense bushes offer protection to many small 
animals. In short, while the forest does not offer the 
rich pasturage of the steppe in summer, it offers greater 
advantages in winter, and especially greater reserves 
of food. 

One result of this is that on the whole the habit of 
migration is less marked in the animals of the temperate 
forest than in steppe ones. It does occur, but, on the 
other hand, both tundra and steppe animals may seek 
the forest in winter, and the greater uniformity of con- 
ditions in the forest prevents migration occurring on 
the same scale as in steppe and tundra, where areas 
of abundance even in the summer season alternate 
with others where famine reigns. "'^•^^4^' 

As a consequence of the fact that the forest onera^' 
a refuge to animals from other areas, we find that its 
denizens may be divided into two groups. We have 
forms like the squirrel, the dormouse, the lynx, the 
woodpecker, the tree-creeper, the tree-frog, and so 
forth, which are structurally adapted for forest life, 
and are not at home elsewhere, and we also find animals, 
like some kinds of deer and wolf and fox, which show 
no very special adaptations to forest life, but which 
visit the forest for shelter or for food. 

We have already noted that the northern limit of 
the forest is determined by adequate summer warmth. 
Its southern limit depends upon much more complicated 
factors, especially upon the rainfall, and the absence of 
drying winds in winter, when the coldness of the soil 
prevents absorption. A small rainfall, limited to the 
summer months, favours grass rather than trees, and 



38 THE TAIGA, OR CONIFEROUS 

their slow rate of transpiration makes conifers more 
tolerant than broad-leaved trees of unfavourable con- 
ditions. The consequence is that in Asia we find 
a band of predominantly coniferous forest separating 
the tundra from the steppes of the central region, this 
forest, which is markedly uniform in character, being 
called the taiga. Its important trees are the Siberian 
larch and the Siberian fir ; the Cembra pine, important 
for its edible seeds, eagerly relished by many animals ; 
with many minor forms, such as juniper, bird cherry, 
mountain ash, &c., important in that they bear edible 
fruits. In addition the taiga resembles the tundra in 
its great wealth of berry-bearing bushes, such as 
cranberries, crowberries, whortleberries, &c., especially 
abundant in clearings, and in areas devastated by 
forest fires. 

Lianes and creepers are t3rpicaUy absent, and the 
taiga as a whole is much less dense than the tropical 
forest. The result is that we have no animals of purely 
arboreal habit, such as occur in the equatorial forests, 
and on the whole arboreal adaptations are few. Very 
many of the inhabitants of the taiga possess the power 
of climbing without showing any great modification of 
structure. 

In North America, especially in the eastern part of 
Canada, a belt of forest of very similar characters occurs. 
The species of conifers are different, but the general 
aspect of the forest is the same, and its inhabitants 
show a general resemblance to those in the Old World. 
Under the name of taiga animals, therefore, we shall 
describe the inhabitants of the coniferous forests of 
both the eastern and western hemispheres. 

The important mammals of the taiga belong to three 
orders ; they are ungulates, or rodents, or carnivores. 



FOREST, AND ITS FAUNA 



39 



There are in addition a few bats and a few insectivores, 
but the predominant forms belong to the orders named. 
We shall begin with the ungulates, as including the 
largest and most obvious of the inhabitants of the 
forest. 

With the exception of the wild boar {Sus scrofa), 




Fig. 3. The Wapiti of the American forests, often miscalled Rocky 
Mountain ' elk '. {Photo by the Biological Survey, U.S.A.) 

which just penetrates the Asiatic taiga from the south, 
and excluding from consideration such forms as sheep 
and goats, really mountain animals, we may say that 
the ungulates of the taiga consist of deer. Deer are 
typically forest-haunting animals, though some of them 
feed on the outskirts of the forests, and a few species 
inhabit open plains, especially in South America, where 
large hoofed mammals are few. Except in South 
America, the place of deer on grassy plains is taken by 



40 THE TAIGA, OR CONIFEROUS 

antelopes, especially abundant in Africa, where deer are 
altogether absent. High up on mountains also, their 
place tends to be taken by sheep, goats, and allied 
forms. The Eurasiatic continent, which is rich in 
forests, is rich also in species of deer, but many of 
these are confined to tropical and subtropical regions, 
leaving relatively few to occur in the taiga proper. 
So far as these forms gc there is a close resemblance 
between the eastern and western halves of the 
continent. 

The fact that deer are characteristic animals in the 
taiga is in itself sufficient to enable us to draw certain 
conclusions in regard to the nature of the region. When 
ungulates occur in tropical forests they are mostly 
small animals, with narrow compressed bodies, which 
allow them to glide through the brushwood. Deer 
are not only big animals, but the broad, spreading 
antlers of the male would make rapid movement 
through a dense wood impossible for him. Some 
authorities regard these antlers as evidence that deer 
have only recently taken to wooded regions ; their 
presence at least excludes the animals from very 
dense thickets. 

In both hemispheres there are taiga varieties of the 
reindeer, and both have elk or moose (Alces machlis). 
In the Asiatic taiga, the red deer {Cervus elaphus) 
occurs, with closely related forms of similar habits, 
such as the maral stag (C. maral). Though these forms 
do not occur in Canada, the wapiti (C. canadensis) is 
a nearly related species. America has in addition the 
Virginian deer {Cariacus virginianus), belonging to 
a group numerously represented further south, and 
distinguished by the great development and curious 
structure of the antlers. In the Asiatic taiga the 




Flo. 4. The Elk or Moose of Alaska. 
{Photo by the Biological Survey, U.S.A.) 




«5 



P^ 



FOREST, AND ITS FAUNA 41 

small roedeer {Capreolus caprea) also occurs, and the 
musk-deer (Moschus) is found occasionally, though its 
true home lies further south. The last is an aberrant 
form, almost hare-like in its habits, and much per- 
secuted for the sake of the scent gland of the male 
(see p. 85). 

Most of the animals above mentioned are at least 
largely forest-feeders. That is, twigs and leaves both 
of coniferous and deciduous trees, berries, nuts, &c., 
bulk largely in their diet, and grass is relatively less 
important. The most northerly forms of those men- 
tioned are the woodland reindeer and the elk, both 
very characteristic of the taiga. In North America the 
woodland reindeer is larger than the tundra form, 
perhaps because it is better fed, and chiefly haunts 
marshy ground. Within the forest, as outside of it, it 
depends largely upon mosses and lichens. In winter it 
leaves the swamps for the dense forests on the higher 
ground. 

In the Asiatic taiga some interesting observations 
on woodland reindeer have recently been made by the. 
members of Mr. Carruthers' expedition to Mongolia. 
Here, on the Sayansk divide, the members of the 
expedition found traces of a forest-haunting form 
which spends the summer in the rhododendron scrub, 
near the upper Limit of the forest. In the winter the 
animals seek the open hill-tops, which are swept bare 
of snow by the wind, and there feed upon ' reindeer 
moss '. 

The elk in both the Old and New Worlds is a true 
forest animal, compelled to feed upon trees and bushes 
by the fact that its long legs and short neck prevent it 
from grazing on the ground, except where the grass is 
very long. 



42 THE TAIGA, OR CONIFEROUS 

The red deer seem to feed chiefly on the outskirts of 
the forest or in the open glades, but the American 
wapiti eats a considerable amount of leaves and twigs. 
The Virginian deer also eats a large amount of forest 
produce, sharing with many other animals, both birds 
and mammals, a great fondness for beech mast, which 
it obtains in winter by pawing away the snow. It 
extends into Canada, but its true home is rather further 
south than the taiga proper. 

The most important rodents of the taiga are the 
various kinds of squirrels, such as the true squirrels 
(Sciurus), the striped squirrels or chipmunks (Tamias), 
and the flying squirrels (Sciuropterus) ; the beaver 
(Castor) ; the Polar hare, which extends into the 
forest region, though it is not common there. The 
American taiga also lodges the Canadian porcupine, 
an arboreal animal, the musquash (Fiber), a swamp 
animal, and the American variable hare in addition to 
the Polar hare. 

The squirrels form a very interesting group, showing 
progressive adaptation to arboreal life. The Siberian 
striped squirrel or chipmunk {T. asiaticus) is an example 
of a ground form which occurs in both North America 
and Asia, though North America has other species in 
addition. The chipmunks feed on nuts and seeds, of 
which they store large quantities for the winter, and, 
like the true squirrels, they hibernate. They differ, 
however, in living mostly on the ground, where they 
often excavate holes. They can climb trees, but are 
not nearly so agile as the true squirrels. The next 
stage is represented by the American red squirrel or 
chickaree {S. hudsonianus), which is a graceful and 
agile climber, but spends a good part of its time upon 
the ground, where it sometimes excavates holes. Our 



FOREST, AND ITS FAUNA 43 

common British squirrel {S. vulgaris), widely distributed 
in the more northerly parts of Asia, as is well known, 
rarely descends to the ground, and has great powers of 
leaping. It shows interesting colour variations, tend- 
ing to be darker in colour in the colder parts of its 
range in summer, and turning white in winter where 
the climate is severe. It will eat almost any forest 
product, and hibernates during winter. The final stage 
in the mastery over the forest is represented by the 
flying squirrels, which are furnished with a parachute 
by means of which they can take long leaps from one 
tree to another, and thus obviate the risks due to 
a descent to terra firma. Though chiefly inhabitants of 
the tropical forests of Asia, one species occurs in tem- 
perate Asia and one in temperate North America. 

The beaver, which haunts the streams flowing through 
wooded regions, was once widely distributed over the 
cooler parts of the northern hemisphere. The American 
species, if not identical with the Eurasiatic one, is at 
least very nearly allied. Beavers feed upon bark and 
twigs, and also upon the roots, &c., of such plants as 
water-lilies. 

While the porcupine of the warmer parts of Asia 
inhabits rocky country, the porcupine of Canada is 
a purely arboreal animal in habits, though it does not 
possess the same adaptations to this mode of life as 
are exhibited by its southern allies, the tree-porcupines 
of South America, Mexico, &c. The Canadian form 
{Erethizon dorsatus) follows the taiga to its northern 
limit, and also follows the western coniferous forest to 
its southern limit. It spends the greater part of its 
time in the trees, though the nest is usually made on the 
ground among stones. The food consists of leaves, 
bark, twigs, beech mast, and other nuts, and the 



44 THE TAIGA, OR CONIFEROUS 

animals are stated to defoliate completely the trees 
they attack. 

As regards the carnivores, the special features of the 
northern forests are the relative poverty in true cats, 
so abundant in tropical forests generally, and the 
wealth of arboreal animals of the weasel family, which 
are most abundant in temperate latitudes, and take 
there the place of the true cats and civets elsewhere. 
The bears also are characteristic of temperate forests, 
though not confined to them. 

There is a close resemblance between the carnivores 
of the American and Siberian taigas. Thus in both are 
found lynxes, the common wolf, the common fox, bears, 
martens, the glutton, and among less purely forest 
forms, weasels, stoats, minks, and badgers. In Siberia, 
especially in the south, the tiger is sometimes found, 
while in the Canadian taiga the puma {Felis concolor) 
does not occur, although it is common in the coniferous 
forest of the Rocky Mountains. The wild cat {Felis 
catus) of the wooded parts of Europe does not occur in 
the Siberian forest, while it is altogether absent from 
America. An animal found in the Canadian forests, 
but with no Old World representative, is the skunk 
{Mephitis mephitica), a member of a group charac- 
teristic of South America, and the only one which 
ranges far north. 

The lynxes are represented by the common lynx 
{Felis lynx) in Siberia, and by a closely related species 
{F. canadensis) in the woods of Canada. They are s,,^ 
expert climbers, and are true forest animals, but the 
Canadian form is stated to feed chiefly on hares and 
birds of the grouse family, so that it must find its food 
largely on the ground. The common woK is not 
specially fitted for forest life ; it lives either in the 



FOREST, AND ITS FAUNA 45 

woods or in the open, wherever food can be easily 
obtained. The fox with its burrowing habits is more 
of a forest animal, but only because in the woods it 
finds the necessary shelter and abundant food. It has 
no special adaptations to life there. 

In addition to wolf and fox Siberia has another 
member of the genus Canis, in the form of the Siberian 
wild dog (C. alpinus), which apparently haunts the 
high Alpine forests, as well as open country. 

The brown bear ( Ursus arctos) occurs in the Siberian 
taiga, as in the woods of the temperate region of the 
Eurasian continent generally. It can climb, though it 
is not so agile as some of its relatives, and, like all the 
bears, it takes a large amount of vegetable food. It is 
stated to be particularly fond of the edible seeds of the 
Cembra pine, and climbs the pines in search of them, as 
well as seeking to rob the peasants' stores. Like its 
relatives also it is very fond of honey. In the taiga of 
North America it is replaced by the black bear ( Ursus 
americanus), of similar habits. The grizzly {U. horri- 
bilis) is only found in the western forest. Both the 
black and brown bears eat fish and other aquatic 
animals in addition to warm-blooded forms, nor do they 
disdain insects. 

In the Siberian forests two kinds of martens occur, 
the pine-marten [Mustela martes) and the more valuable 
sable {M. zihellina), with a more northerly range and 
a more valuable coat. Both are thoroughly arboreal, 
though both descend to the ground upon occasion. 
Closely related is the American marten {M. americana), 
which is of similar habits, while the fisher marten 
{M. pennanti), in spite of its name, is also largely 
arboreal. It occurs throughout the greater part of 
North America, haunting mountain regions in the 



46 THE TAIGA, OR CONIFEROUS 

warmer parts of its range. The polecats, of which one 
{M. eversmannia) occurs in Siberia, the common weasel 
{M. vulgaris), found both in Northern Asia and in 
Northern America, and the stoat or ermine (M. erminea) 
as already indicated, are not definitely forest animals, 
though they are found there as well as elsewhere. The 
mink {M. vison) of North America, and the Siberian 
form {M. siberica) haunt streams and lakes, and are 
forest animals to the extent that localities suitable to 
their habits often occur within forest areas. 

On the other hand, the wolverene (Gulo luscus), 
a fierce and voracious carnivore, is chiefly found within 
the forest, where it preys upon all manner of small 
mammals and birds, and even attacks weakly or 
disabled deer. 

The common badger (Meles taxus) is found in the 
Siberian forests, and, though a burrowing form, occurs 
chiefly in woods. On the other hand, the American 
form [Taxidea americana) is chiefly a prairie mammal, 
and feeds largely upon the prairie marmots (see p. 64). 

Passing now to the birds, we find that the forest is 
rich in specially adapted forms, and that in addition 
there are large numbers of migrants who spend part of 
their time there. The forest gives relative security 
during the dangerous period when brooding is taking 
place and the young are being reared. The absence or 
paucity of snakes in the northern forest also, and the 
complete absence of monkeys as well as of the man^ 
carnivorous or egg-eating animals which haunt tropical 
forests, increase the value of the northern forest from 
the birds' standpoint, and help to account for the 
number of species found there in summer time. Among 
forms which are especially abundant in northern 
forests, or especially adapted to life there, we may 



FOREST, AND ITS FAUNA 47 

note the grouse and their alHes ; the grosbeaks and their 
relatives the crossbills ; the woodpeckers and wryneck ; 
the nutcrackers, jays, and their allies. 

Grouse belong to the same family as the ptarmigan, 
and are especially characteristic of northern latitudes. 
The abundance of berry-bearing bushes, of which we 
have already spoken, both in the tundra and in the 
taiga, is an important factor in their distribution, for 
these berries constitute a considerable part of their 
food. In the Asiatic taiga we find the black grouse 
{Lyrurus tetrix), the larger capercaillie {Tetrao urogallus), 
and the hazel grouse {Tetrastes honasia), while in the 
Canadian forest is found the Canadian grouse {Cana- 
chites canadensis), often called a partridge, and also the 
ruffed grouse {Bonasa umbellus). 

The woodpeckers are birds showing remarkable 
adaptations to an arboreal habitat. The feet are well 
fitted for climbing, and the most highly specialized 
forms have stiffened tails, which aid in the climbing 
process. The beak is powerful and chisel-shaped, 
enabling the birds to excavate holes in wood, and also 
to lever off bark, while the long, viscid, worm-like 
tongue enables them to capture the insects thus 
exposed. Woodpeckers are very widely distributed, 
a few only ranging into the northern woods. Among 
these are the green woodpeckers (Gecinus), found in 
the temperate regions of the Old World, and the 
spotted woodpeckers (Dendrocopus), of both Old and 
New Worlds. Related is the curious wryneck (lynx 
torquilla), found in summer in Northern Europe and 
Asia, which is without the stiff tail and climbing habits 
of the woodpeckers. 

We have spoken of the edible seeds of the Cembra 
pine, and of the appreciation in which they are held 



48 



THE TAIGA. OR CONIFEROUS 



by many inhabitants of the Siberian taiga. Though 
the seeds of other conifers have not the same wealth 




Fig. 6. The Three-toed Woodpecker of North America. Note the 
characteristic attitude, and especially the position of the tail. (Photo 
by the Biological Survey, U.S.A.) 

of food products, yet they also are edible to many 
animals, and form a much sought after food supply. In 



FOREST, AND ITS FAUNA 49 

both the Siberian and Canadian taiga they form a very 
large part of the natural food of the pine grosbeak 
{Pinicola enucleator), a gorgeous bird related to the 
bullfinch, and of the crossbill {Loxia curvirostra) , also 
with bright-coloured plumage. Pine cones, it will be 
remembered, ripen slowly, and during the ripening 
process the seeds are carefully protected by the closing 
of the scales, so that their extrication is a matter of 
difficulty. The forester is constrained to apply heat to 
obtain the seeds without damage, but the crossbills 
have the beak converted into an instrument by means 
of which the seeds are readily prized out. More slashing 
are the methods of the nutcracker {Nucifraga caryo- 
catactes), which in the Alps, as in Siberia, may be seen 
breaking the cones of the Cembra pine to pieces with 
its powerful bill. The western coniferous wood of 
North America is inhabited by another species. Re- 
lated to the nutcrackers are the magpies and jays, the 
latter represented in the eastern taiga by the Siberian 
jay {Perisoreus infaustus), with soft fluffy plumage of 
a reddish colour. 

Reptiles and amphibians are few in number in the 
northern forest, the former especially. Among am- 
phibia, frogs and toads haunt the pools and swamps, 
an important form being the large bull-frog {Rana 
catesbiana) of North America, which is exceedingly 
voracious, devouring fish, young water-birds, &c., and 
derives its common name from its noisy croak, which is 
compared to the roaring of a bull. The tree-frogs 
(Hylidae), with their usually greenish colour and the 
curious adhesive pads at the ends of the toes, by means 
of which they keep their foothold, have a much wider 
distribution in America than in the Old World. In 
the Eurasiatic continent the common tree-frog {Hyla 

1404 D 



50 THE TAIGA, OR CONIFEROUS 

arborea) of Europe just reaches the south of the taiga, 
but the tree-frogs of North America have a more 
northerly extension. 

In insects the northern forests are rich, for the 
perennial vegetation feeds many herbivirous forms, 
and many carnivorous or parasitic forms prey upon 
these. Many of the beetles especially are important 
pests from the point of view of the forester. 

As examples of wood-eating forms we may mention 
the wood-wasps (Sirex), of which a large species {S. 
gigas) often appears in summer-houses or other wooden 
erections in Britain, where it has been introduced with 
pinewood. The adult female has a boring apparatus, 
by means of which she bores a hole in trunks of pine 
trees in order to lay her egg at the bottom of the 
excavation. The wood-wasps are preyed upon by 
ichneumon flies, whose delicate senses enable them to 
find the burrows of the wasps, when they insert their 
long ovipositors and lay their eggs close to the wasp's 
egg, so that the resultant larvae may prey upon the 
wasp larva. There is here a singularly delicate adjust- 
ment between host and parasite, comparable to the 
relation which exists between the length of the pro- 
boscis of certain butterflies and the length of the tubes 
of the flowers which they visit. 

Another form which feeds in the pine woods is the 
pine saw-fly (Lophyrus pini), whose larvae feed upon 
the needles, sometimes in countless numbers. 

Wild bees also occur in the woods, the forms which 
store up honey extending much further north in the 
Old World than in the New. In Asia wild honey bees 
reach the Arctic circle, while in North America, accord- 
ing to Marshall, they scarcely pass latitude 50° N. The 
honey is greatly prized by bears, who rob the nests 



FOREST, AND ITS FAUNA 51 

without regard to the stings of the bees, from which 
their thick coats doubtless protect them. 

Refeeences. Kobelt's book, already mentioned, gives a full account 
of the taiga animals, and descriptions will also be found in Brehm's 
From North Pole to Equator (in translation, London, 1896). As the 
inhabitants of the taiga are mostly those characteristic of the temperate 
regions of the Northern Hemisphere, full accounts of them will be found 
in the books mentioned at the end of chapter x. Most descriptions of 
journeys through Siberia also give some account of the taiga animals. 



D 2 



CHAPTER III 

STEPPE FAUNAS AND THE TEMPERATE 
STEPPES OF ASIA AND NORTH AMERICA 

To the south of the coniferous forest of Asia hes 
a belt of varying width, characterized by the absence 
or scarcity of trees, and by the periodical growi:h of 
grasses and other herbaceous plants. This belt of 
steppe land is continually merging into desert, the cold 
desert of the high uplands, or the warm desert of the 
rainless regions to the south. Similarly, the forest sends 
long feelers into it, wherever the banks of a water-course, 
or some favouring condition of soil or local variation of 
climate, make this possible. As Central Asia generally 
is a country of high mean elevation, and as it is remote 
from the sea, the climate is continental in character, 
very hot in summer and very cold in winter. The 
region is also continually swept by very severe storms, 
injurious alike to plant and animal life. Further, 
though the rainfall is always slight, and chiefly con- 
fined to the summer period, there is some reason to 
believe that it is subject to great variation, perhaps 
cyclical in character. 

This very brief description may be said to sum up 
the main features of regions of temperate steppes, and 
the peculiar conditions cause them to be inhabited by 
special types of animals. Some of the conditions which 
we noted in the tundra are here repeated, for indeed 
the tundra is but a special type of steppe. Thus in 
both we have a seasonal and highly local abundance of 



STEPPE FAUNAS OF ASIA AND AMERICA 53 

food, and also a seasonal and local scarcity. If the 
rains of early summer are abundant in the steppe there 
is an extraordinarily rapid awakening into life on the 
part of the steppe plants, resulting in a great abun- 
dance of food for the herbivores of the region. If the 
rains fail, scarcity reigns, and it comes in any case as 
soon as the favourable season is past ; that is, alike in 
the height of summer and in the depth of winter. But 
local conditions produce minor variations in climate, 
altitude being one of the most important of these con- 
ditions. For this reason there are frequent alternations 
of famine and plenty, alike in time and space. Like 
the tundra animals then, the steppe animals tend to be 
social, to move about in flocks from one region of 
abundance to another. But as the wealth of the steppe 
is greater than that of the tundra, they are far more 
numerous, and far more diverse. Like the tundra 
animals as a whole, they attempt to escape unfavour- 
able conditions by migration, and as these migrations 
must be rapid, to prevent death by starvation occurring 
between one region of pasturage and the next, the 
steppe animals are mostly swift, with special adapta- 
tions to ensure rapidity of movement. 

The herbivores, always, as we have seen, necessarily 
the majority, are far more exposed in the open steppe 
than in the forest, and therefore they are either bur- 
rowers, or have singularly keen senses, enabling them 
to perceive danger from afar. The social instinct also 
is here of great aid. In some cases, as with the wild 
asses, the strength of the male enables him to protect 
the females and young from attack. As the safety of 
the species depends in this case upon the strength of 
the male, we find that he must win and keep his post 
as leader and defender by his strength, and that he is 



54 STEPPE FAUNAS AND TEMPERATE 

deposed by a younger male so soon as his powers begin 
to fail. 

Again, the social instinct is an aid in another way. 
The more helpless forms, such as the rodents, usually 
appoint sentinels when they feed, these sentinels giving 
warning of the approach of danger in time for the 
party to seek safety in flight or underground. In the 
forest, where food is more uniformly distributed and 
the natural shelter greater, social animals are less 
frequent. 

Another marked feature of steppe animals is their 
great fertility, seen alike in the steppe rodents and in 
insects like the locusts. This is associated with the 
risks of the natural habitat — risks of drought and con- 
sequent lack of food, risks of storm, risks associated 
with winter cold and summer heat. In Central Asia 
the dreaded ' buran ' or hurricane may practically 
exterminate all life within a given area, except such 
animals as can find a refuge underground. As such 
storms are frequent, great natural fertihty is necessary 
to repeople the devastated regions. Similarly, a season 
of deficient rainfall, or a series of such seasons, must 
kill out large numbers of animals. 

We have already seen that this fertihty of steppe 
animals is associated with strong migratory instincts. 
Now no natural barriers separate steppe regions from 
the neighbouring areas of forest, of desert, of semi- 
desert, and so forth. We find then, as a special character 
of steppe animals, the fact that they tend periodically 
to overrun the means of subsistence within their own 
region, and therefore to flow out into the neighbouring 
regions. The direction of the winds and the position 
of Europe on the western border of a great continent 
give it a moist climate, and led to its being forest-clad 



STEPPES OF ASIA AND AMERICA 55 

almost throughout till man interfered, though the steppe 
region of Asia is continued into it through Southern 
Russia and part of Hungary. We find then that since 
the close of the glacial period Europe has been con- 
tinually liable to incursions of steppe animals from 
Asia, some of which, like the hamster, have kept their 
hold, while others, like the saiga antelope, rapidly 
died out. 

Another character of the animals of the temperate 
steppe is the prevalence of hibernation among them. 
The tundra is too cold for hibernation to be practised 
to any great extent, and the shelter and presence of 
food even in winter in the forest makes it relatively 
infrequent there. But the animals of the steppe can 
only find in burrows and in sleep protection against 
want of food and extremes of temperature, so that here 
both aestivation and hibernation may occur. The 
squirrels in the fir woods wake whenever the temperature 
rises in winter, just as the fir-tree itself becomes active 
whenever the temperature permits. But the plants of ^ 
the steppe disappear beneath ground so soon as their = * 
brief period of activity is over, and their quiescence is 
reflected in that of many of the steppe animals. 

Large areas of land almost devoid of trees, and 
clothed, at least at times, with grasses and herbs, occur 
in many other temperate regions besides Asia and 
South-eastern Europe. A great area of land of this 
type extends from the border of the Canadian forest 
southwards through the United States in the region 
west of the Mississippi river, nearly to the Gulf of 
Mexico. Similar areas occur in the Argentine and in 
Patagonia in South America, in South Africa, and in 
the south-eastern part of Australia. By extension the 
term steppe can be applied to all these regions, and 



56 STEPPE FAUNAS AND TEMPERATE 

there are other large areas in Africa and in the north of 
South America where open park-like country occurs, 
with trees scattered among the grass, and such land has 
some of the characters of a steppe. Again, all the great 
deserts of the world are fringed by semi-arid areas, 
displaying the general characters of a steppe. 

The great interest of the steppe areas is that, espe- 
cially in Asia and Africa, they are the natural home of 
very many of the great ungulates, the most highly 
specialized of which are steppe animals. In North 
America the steppe lands, within the human period 
at least, have been inhabited only by few species of 
wild ungulates, but of these few the bison was repre- 
sented by countless numbers of individuals until it 
was exterminated by the white man. In South America, 
within the human period, but prior to the immigration 
of the white, large ungulates were almost absent. No 
horse, no relative of cattle or sheep or antelope cropped 
the herbage of the great plains, but their place in 
nature was taken by enormous numbers of rodents, 
which reached here a size not attained elsewhere. 
Again, in Australia no ungulate whatever occurred, 
and the natural pasture was utilized by marsupials or 
pouched animals, of which the most important grass- 
eating form is the kangaroo. 

That South America has few native ungulates and 
Australia none are two of the most interesting facts in 
geographical distribution, but the fact that ungulates 
introduced by the white man into both countries have 
flourished apace makes it unnecessary for us to suppose 
that any natural obstacle to their presence there 
existed. We may then say generally that the steppe 
regions of the world are the regions which form the 
natural home of the ungulates most valuable to man. 



STEPPES OF ASIA AND AMERICA 57 

It is the steppes of the more remote parts of the world 
which now support the vast herds of sheep, horses, and 
cattle necessary for the wants of civilized communities. 
Further, as steppe regions do not require to be cleared 
of trees, and, where the rainfall is sufficient, often pro- 
duce abundant crops, we find that it is in the steppe 
regions that the cultivation of cereals is being most 
vigorously pushed at the present time. The regions of 
dense population are mostly regions of abundant rain, 
and therefore were once forest regions. Formerly these 
watered lands were liable to be periodically flooded by 
the overflow of the fertility of the steppes. This great 
tide is now being gradually regulated, and the steady 
stream of wheat, of wool, of meat, and so forth, which 
pours into the civilized world, is the biological equiva- 
lent of the flocks of rodents and the flights of locusts 
which the steppe sent out in earlier days, and of the 
hordes of wandering nomads which came later. 

To this general account we may add a few words on 
the special conditions, climatic and other, found in the 
steppes of temperate Asia, the region to which the 
following description specially refers. Steppe condi- 
tions reign over that great area of Central Asia which 
is practically ringed by mountain chains, as well as to 
the west of it, but the fauna throughout this area is 
not uniform. The mountain chains themselves have 
their own characteristic animals, and the plateau of 
Tibet, with special conditions of climate, has a peculiar 
fauna of its own. Excluding Tibet and the mountain 
chains then, we have a great steppe and desert area 
which extends from the eastern base of the Pamirs to 
the Khingan Mountains, and is separated from the 
forest region to the north by the great area of elevated 
ground in which the Siberian rivers arise, and from the 



58 STEPPE FAUNAS AND TEMPERATE 

wooded regions of China to the south-east by mountain 
chains. Through the Dzungarian Gate this area, to 
which the general name of Desert of Gobi or Shamo 
may be given, is continuous with the extensive band of 
steppes which runs through Russian Turkestan to the 
Aral and Caspian seas, is continued through Southern 
Russia in Europe into Hungary, and is bounded to the 
south-west by the plateau of Persia. But uniform con- 
ditions do not reign throughout this great area, which 
shows many alternations of fertihty and aridity. Thus 
the snows of the Pamirs water much of Russian Turke- 
stan through the Amu Daria and the Syr Daria, and 
this westerly region as a whole has a much milder 
winter climate than the easterly region, permitting of 
the extension into it of animals really peculiar to the 
southern steppe and desert regions, those characterized 
by the absence of severe winter cold. 

Climatically, as we have seen, the general features of 
the steppes of temperate Asia are the great range of 
temperature, the hot summers and the bitterly cold 
winters, and the small precipitation, which tends to 
occur in late spring or early summer, giving a dry 
winter and a dry summer and autumn, which makes 
the growth of trees virtually impossible. The frequency 
of dry east winds in winter is an important feature in 
checking the growth of perennial plants, except such as 
die down to the ground. As indications of the nature 
of the climate, we may note that at Orenburg the 
mean January temperature is 4° F., and the mean July 
70° F., while the mean annual precipitation is only 17", 
with a June maximum, but no absolutely dry month. 
Further to the east much lower winter temperatures 
occur ; thus Sven Hedin found temperatures of — 17° F. 
in the Tarim basin, and the river here is frozen for three 



STEPPES OF ASIA AND AMERICA 59 

and a half months every year. Even the Amu Daria, 
in a western region of relatively mild winters, is frozen 
for about a month every year. The steppe animals are 
thus subjected to very unfavourable natural conditions, 
but the high summer temperature, especially during 
the rainy season, means a great intensity of life for 
a short period. 

In giving a brief account of steppe animals, we shall 
limit ourselves chiefly to the steppes of Central Asia 
just described, and, as before, will begin with the 
ungulates, here especially important. 

Perhaps the most characteristic of the steppe ungu- 
lates is the saiga antelope {Saiga tartarica), an ungainly 
animal with rather short legs, the male having a peculiar 
swelling on the face, which makes it appear hook-nosed. 
The animal occurs in thousands in the Kirghiz steppes, 
and the fact that its yellowish coat becomes almost 
white in winter suggests the severity of the climate in 
its home. Formerly it had a much wider distribution 
to the west, its remains having been found even in 
Southern England, as well as in Belgium and Southern 
France. In the historic period it has been gradually 
retreating eastwards, thus losing the ground which its 
ancestors conquered in the ages when steppe con- 
ditions were more widely spread than at present. The 
antelopes are also represented in the steppes by two 
kinds of gazelles, the so-called Persian gazelle (G. sub- 
gutturosa), which extends to the Gobi desert, and the 
Mongolian gazelle {G. gutturosa), a somewhat larger 
animal ; but, generally speaking, the gazelles are more 
characteristic of the warmer deserts to the south. 

No less than three kinds of horse-like animals haunt 
the Asiatic steppe — the tarpan or wild horse [Equus 
caballus), Prejevalski's horse {E. prejevalskii), and the 



60 STEPPE FAUNAS AND TEMPERATE 

kiang or wild ass {E. hemionus). The tarpan is now 
limited to the regions of the steppe most remote from 
human influence. Like its allies it goes about in small 
troops under the leadership of an old male, and has 
extraordinarily acute senses and great swiftness. In 
winter its. coat is so thick as to form a kind of fur, 
and it obtains food by scraping away the snow from 
the ground. It is almost uniform in coloration, and of 
a dun colour. Prejevalski's horse is of a similar colour 
above, but is almost white underneath. Such a dun 
tint is common in steppe and desert animals, and is 
doubtless protective. In the kiang there is a dark 
stripe down the back, and traces of striping on the 
limbs, but the body is of a uniform darkish colour, 
instead of being striped as in the African zebras. The 
kiang (see Fig. 16) inhabits the higher parts of the 
steppes, and occurs at great heights in Tibet. 

Still another group of ungulates is represented in the 
steppes by the Bactrian or two-humped camel {Camelus 
hactrianus), which with its long hair, moderately short 
legSj and hard feet is as well fitted for the hilly and 
rocky regions of the steppes, as is the one-humped 
camel for the sandy deserts to the south. The animal 
feeds largely upon the bitter saline plants of the steppes, 
and will drink saline and brackish water, so that it is 
a typical inhabitant of the salt steppe. The two humps 
allow for the storage of fat when the animal is well fed, 
and thus permit it to withstand periods of semi-starva- 
tion. Its appetite is, moreover, remarkably catholic, 
for, according to Prejevalski, it will devour all sorts 
of animal matter if vegetable food fails. 

Taking antelopes, horses, and camel as representa- 
tives of the ungulates of the steppes, we may pass on 
to the consideration of the rodents, which are numerous 



STEPPES OF ASIA AND AMERICA 



61 



both as to individuals and as to species, and often show 
some curious adaptations to steppe Hfe. 

A point of very considerable interest in regard to 
the steppe rodents is that there is much general resem- 
blance between those inhabiting Asia and those of 
North America. This is the more remarkable in that 
there is no resemblance in regard to the ungulates of 




Fiti. 7. Transport Camels in the Australian Desert. 

the two regions. The prairies of North America have 
no antelope, no camel, no wild horse nor ass. Their 
chief ungulate was formerly the bison (Bos americanus), 
while the bison of the temperate regions of the Old 
World was a forest-dwelling animal, found in Europe, 
but not in the steppes of Asia. The other important 
ungulate of the North American prairies is the prong- 
buck (Antilocapra americana), an animal related to the 
antelopes, but differing markedly in the fact that the 



62 STEPPE FAUNAS AND TEMPERATE 

horns are shed annually and are branched. The con- 
trast between the living, or recently exterminated, 
ungulates of the Old and New Worlds is the more 
remarkable when we find that America has many fossil 
horses, though no living ones. 

In proof of the statement just made as to the resem- 
blance between the steppe rodents in the Old and New 
Worlds, we may note that marmots occur in both 
regions, that the sushks of Asia are represented by the 
forms called gophers in America, which belong to the 
same genus, and that the jumping mouse of the American 
prairies takes the place of the jerboas and their aUies 
in the Old World. As the adaptation to steppe life is 
similar, we shall refer chiefly in the following descrip- 
tion to the rodents of the Asiatic steppes. 

The susliks (Spermophilus) are related to the squirrels, 
but the common steppe form {S. citillus) differs in the 
very short tail and the minute ears, both adaptations 
to the terrestrial and burrowing habit, and markedly 
contrasted with the long tail and large tufted ears of 
the common squirrel. Like other steppe rodents the 
sushks are social and burrowing animals, hibernating in 
winter, but storing in autumn a large collection of roots, 
seeds, berries, &c., for winter use. Like the squirrels, 
they are not averse to a certain amount of animal food, 
taking small birds and their eggs when occasion offers, 
and also small rodents belonging to other genera. 

The marmots (Arctomys) form an interesting genus, 
with representatives both on mountains and in the 
steppes. We shall see later that it is not unusual to find 
relationships between steppe and mountain animals, 
a fact which has a double significance. Li the first 
place, just as the tundra forms a steppe because it is 
too remote from the Equator for tree growth to occur, 




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STEPPES OF ASIA AND AMERICA 63 

so the upper parts of mountains form steppes because 
the elevation prevents forest growth. Again, it is 
believed that in those parts of the world recently sub- 
jected to glaciation there was a period, after the retreat 
of the ice, when the climate was unsuited to trees, lead- 
ing to a wide extension of steppe conditions. This 
brought in its turn a wide extension of steppe animals, 
which, with the gradual improvement of the climate, and 
the return of forest-haunting forms, were driven up 
the mountain sides to the Alpine regions. If this be so, 
then the shriU whistle of the Alpine marmot, so common 
a sound in the mountainous regions of Switzerland in 
summer, not only recalls the conditions of the Asiatic 
steppes, but also brings back a time when much of 
Europe was in the condition in which the steppes are 
to-day. The Alpine marmot is now limited to the Alps, 
Pyrenees, and Caucasus, the time being far past when 
it also inhabited the low ground. On the other hand, 
the bobac {A. hobac), the characteristic marmot of the 
Asiatic steppes, extends into Europe as far as the 
eastern frontier of Germany. 

Marmots are rather clifmsy animals with heavy 
bodies, short limbs, and usually short tails. The short- 
ness of the hmbs must greatly Kmit the range of vision, 
and the animals have very markedly developed that 
habit of sitting up on the hind Umbs to take a wider 
view which is common in relatively short-legged animals. 
The shortening of the fore-hmbs here gives greater 
purchase in burrowing, the burrows being extensive. 
The food appears to be entirely vegetable, and the 
animals hibernate much more profoundly than the 
susliks. Bobacs occur in very large colonies, and c> 
tunnel the ground in all directions with their burrows. ^ 
According to Kobelt, the result of these excavations is 



64 STEPPE FAUNAS AND TEMPERATE 

to modify the condition of the soil, so that special 
plants appear in the ' marmot gardens ', which can 
thus be recognized from afar. The hemp-leaved nettle 
and wild rhubarb occur especially here, and the presence 
of the large leaves of these plants among the lyme 
grass (Elymus) of the steppes is a very obvious feature, 
while the loosening of the soil by the burrows makes 
progress for horsemen very difficult over the ' gardens '. 

The interesting point is that rodents of similar habits 
seem to inhabit steppe regions in general. Thus the 
prairie marmot {Cynomys Ivdovicianus), a related form 
inhabiting the prairies of North America (Fig. 9), has 
similar habits, while the viscacha of the pampas of 
Argentina, though not very nearly related, shows also 
a general resemblance in habits, and also modifies the 
herbage in the regions of its occurrence. 

A different, though no less perfect, adaptation to 
steppe Hfe is shown by the jerboas or jumping mice. 

In speaking of the marmots we noted that for rapid 
and efficient burrowing, short fore-legs are necessary, 
but, on the other hand, if the hind-legs are also short, 
the animal's range of vision is small, and its speed 
cannot be great. On the other hand, if the legs are 
elongated to give speed, then feeding on the ground 
and drinking become difficult, as is seen in the giraffe 
(Fig. 36). The jerboas show a curious form of compro- 
mise to these varying needs, generally parallel to that 
shown by the kangaroo, which is, however, not a 
burrowing animal. In the jerboas the fore-Kmbs are 
short, thus permitting the animal to burrow, but the 
hind-legs are enormously long (Figs. 37 and 38), and the 
tail also long and capable of helping in the support of 
the body. The animal therefore progresses by leaps, the 
fore-legs not touching the ground at all. In feeding, 



STEPPES OF ASIA AND AMERICA 65 

a crouching position is adopted, the food being carried 
to the mouth by the fore-Hmbs. As in rodents in 
general, the food consists largely of roots, seeds, berries, 
&c., and not wholly of grass, as in the kangaroo and in 
most ungulates. The curious elongation of the hind-legs 
gives such speed that the jerboas can escape their 
enemies by flight, while on the other hand the bobacs 
at once seek their burrows on an alarm, and make 
underground tunnels to the feeding-grounds, so that 
they are never far from an open burrow. Another very 
interesting structural point in regard to the jerboas is 
the reduction of the number of toes from five to three 
on the hind-foot. Among the ungulates we find a 
similar reduction, carried however much further, for 
the horse and its allies have only one toe on each foot. 
This reduction gives speed, and is an adaptation to 
swift movement over a relatively hard surface. 

The commonest jerboa of the steppes is Alactaga 
decumana, the five-toed jerboa as it is called, because 
the lateral toes are present on the hind-feet, though 
they are minute and functionless. Another peculiarity 
of the hind-foot, which it shares with other jerboas, is 
the fusion of the bones which form the sole of the foot 
in man, that is of the metatarsal bones. As a result 
a very strong bone called the cannon bone is formed, 
quite comparable to the cannon bone in the antelopes 
and their allies, though it is formed in a different way. 
This also is an adaptation to ensure swift movement 
over firm ground, for it gives the necessary rigidity 
during the taking of the long leaps. Though the head 
and body together of this animal only measure some 
seven inches, it is stated that it cannot be overtaken 
by a horse, so extraordinarily rapid is its speed. Like 
the other steppe rodents the jerboas are social, forming 

1404 v\ 



66 STEPPE FAUNAS AND TEMPERATE 

burrows in companies. With the vegetable food they 
mmgle insects and the eggs and young of birds, 
especially of the steppe lark. 

The jerboas of the genus Dipus chiefly inhabit the 
hot deserts further south, but some species, notably 
D. sagitta, extend into the steppes. Though the habits 
of the members of this genus are generally similar to 
those of the preceding in their coloration and in their 
intolerance of rain or damp, they are essentially in- 
habitants of arid regions (cf. p. 133). 

In the steppe region are also found the hamsters 
(Cricetus), with a western extension into Europe. But 
though originally doubtless steppe animals, the ham- 
sters, like the bro^^Ti and black rats, though to a less 
extent, have attached themselves to man, and find it 
more profitable to plunder his fields and gardens, than 
to depend upon the precarious vegetation of the steppes. 
They are remarkable for the size and elaboration of 
their burrows, in which they store quantities of corn, 
&c., for winter use. 

Another characteristic genus of the steppe is Lagomys, 
the genus which includes the picas, tailless hares or 
whistling hares as they are variously called. These 
animals are smaller than a rabbit, and are for the most 
part mountain animals, Kving high up among rocks 
and stones in the mountains of Central Asia. In Siberia, 
however, they are found on lower ground, and even 
extend into the tundra region. They form a very 
important part of the food of the carnivores of the high 
steppe, replacing here the lemming of the tundra. In 
MongoHa, L. ogotona occurs in large colonies, and at 
the approach of winter stores up large quantities of 
hay near the openings of the holes. According to 
Prejevalski, these haystacks may weigh 10 kilogrammes 



STEPPES OF ASIA AND AMERICA 67 

(22 pounds), and are sufficiently numerous for it to be 
worth while for the Mongolians to bring their cattle to 
feed upon the pica's stores, and so dispense with the 
trouble of storing fodder on their own account. Like 
some other of the steppe animals, the picas are remark- 
ably resistant to thirst, and can Hve in localities far 
from water, where no rain nor dew occurs for months 
at a time. 

As to the carnivores of the steppe, the tiger, though 
usually regarded as a tropical animal, extends far 
to the north, and occurs in steppe regions, perhaps in 
more than one variety. When nobler game fail, it does 
not disdain the rodents, notably the picas. The special 
cat of the steppe is, however, the manul cat {Felis 
manul), a beautiful animal with a bushy tail, about the 
size of the common cat, and apparently alhed to the 
wild cat of Europe, but, unlike it, a steppe animal. Its 
main food consists of the steppe rodents, and also of 
the ground-nesting birds. The steppe has also its 
special fox, the corsac fox (Canis corsac), which also 
feeds chiefly upon the steppe rodents. Here as else- 
where the ubiquitous wolf also occurs. 

In regard to the birds of the steppe it is noticeable 
that they tend to acquire swiftness in running, thus 
showing parallelism with the mammals. This is 
carried further in the birds of the warm deserts of the 
world, where we have in ostrich, rhea, emu, &c., 
examples of birds without any power of flight, but of 
great fleetness of foot. The reason for this tendency is 
possibly that the steppe or desert does not, like the 
forest, offer safe places upon which to rest. As the 
birds are exposed to danger so soon as they alight, 
which is necessarily upon the ground, fleetness is a great 
advantage to them. 

E 2 



68 STEPPE FAUNAS AND TEMPERATE 

As examples of steppe birds, we may name first the 
bustards, of which the largest form, the great bustard 
{Otis tarda), has been compared in build and habits to 
the ostrich of the Saharan desert. Bustards, though 
good fliers, are fleet of foot, and show a preference for 
open country. They do not seem to drink, and take 
both animal and vegetable food. In addition to the 
form mentioned, the little bustard {0. tetrax) and the 
ruffed or Macqueen's bustard {Hubara undulata) also 
occur, the latter preferring running to flying, and 
having the habit, common among steppe animals, of 
squatting down when undisturbed, so as to take full 
advantage of its protective coloration, but stretching 
itself to its (considerable) height on an alarm in order 
to increase the range of vision over the plain. 

Pheasants, which are bush-haunting birds, just enter 
the region, but Pallas's sand-grouse {Syrrhaptes para- 
doxus) is characteristic, both the young and the adult 
showing a delicately patterned type of coloration which 
is eminently fitted to conceal them in their natural 
habitat. The young are precocious, being able to run 
as soon as hatched. This is necessary in birds whose 
eggs are laid in a mere depression scratched in the 
loose soil. In the steppes the bird is said to feed chiefly 
on the seeds of a member of the Chenopodiaceae called 
AgriophyUum, and it assembles in large flocks in places 
where this plant of the salt wastes is abundant. The 
plant is also reUshed by horses and camels, and its 
seeds are used as food by the nomads as well as by the 
sand-grouse. The sand-grouse shares with many steppe 
animals the peculiarity of being periodically very 
abundant, when it makes incursions on lands adjacent 
to its normal habitat. Flocks of it have appeared at 
various times in Europe, reaching even the British 



STEPPES OF ASIA AND AMERICA 69 

Isles. The bird differs from the bustard in that water 
is necessary to it, and it makes regular daily visits to 
particular drinking-places. 

Very characteristic of the Asiatic steppes are the 
birds belonging to the genus Podoces, sometimes called 
chough-thrushes, which are members of the crow 
alliance, though their exact position is doubtful. 
Though capable of flight, they only fly with reluctance, 
but run swiftly, feeding upon insects and seeds, and 
nesting in bushes or sometimes on the ground. They 
haunt the desert regions where bushes of saxaul and 
tamarisk grow, and do not seem to drink, while the more 
grassy regions of the steppes often swarm with the 
Siberian lark {Melanocorypha calandra). 

In the American prairies game birds are represented 
by the prairie-hen {Tympanuchus americanus), a form 
related to the grouse ; also by the sage-cock {Centro- 
cercus urojphasianus, Fig. 10), which feeds upon ' sage- 
brush ' {Artemisia tridentata) in the western states, just 
as Pallas's sand-grouse feeds upon Agriophyllum in the 
Asiatic steppes ; and by the prairie-chicken {Pedioecetes 
phasianellus). All these can fly rapidly and powerfully, 
but only rise when hard pressed, preferring to run along 
the ground, or squat among the herbage, as means of 
escaping notice. 

In the steppes of both the Old and New Worlds such 
forms as curlews, plovers, snipe, ducks, geese, and so 
on, with many of the smaller singing-birds, are abun- 
dantly represented in the breeding-season, but do not 
show any very notable adaptations to steppe life. 

Reptiles in the steppes and adjacent deserts are not 
numerous in species, but the individuals are often very 
abundant. In that part of the desert of Gobi which is 
called Alashan, lizards belonging to the genera Phryno- 



70 STEPPE FAUNAS AND TEMPERATE 

cephalus and Eremias are very abundant, and show 
special adaptations to desert life, e. g. in coloration, in 
swiftness, in the power of burrowing, and so forth. So 
abundant are they in summer that they attract flocks 
of the demoiselle crane {Grus virgo), which feeds upon 




Fig. 10. Sage-cock. (Photo by the Biological Survey, U.S.A.) 

them. They are also greedily consumed by birds of 
prey, and even by such mammals as wolves and foxes 
and domesticated dogs. In the steppes and deserts of 
Turkestan there occurs a curious gecko {Teratoscincus 
scincus), which has lost the disks on the digits by which 
its alhes chmb, and has acquired curious fringes, which 
enable it to run over the loose sand. Among snakes 
we find the small sand-snake (Eryx jaculus), a harmless 



STEPPES OF ASIA AND AMERICA 71 

form, which extends into Greece, and is interesting 
from the way in which it buries itself in the sand by 
means of its snout ; and the poisonous Trigonocephalus 
halys, dangerous to cattle but not to man, as well as 
vipers and others. 

Amphibians are limited to the regions in the vicinity 
of water, and offer no special features. As regards 
insects we need only note that grasshoppers and locusts 
are very abundant, open grassy plains being the natural 
home of these insects, from which the locusts make 
periodical raids upon cultivated lands. 

Refeeekces. The works of Kobelt and Brehm already mentioned 
give accounts of steppe animals, and reference should also be made to 
any of the natural histories, e. g. the relevant volumes of the Cambridge 
Natural History (London), edited by Shipley and Harmer, or The Boyal 
Natural History (1893-6), six vols., edited by Lydekker, where details 
will be found of the different animals mentioned. A series of articles 
in the American Naturalist, especially 'Cursorial Adaptations in 
Mammals', by Lull (1904), and Tossorial Adaptations in Mammals', 
by Shimer (1903), will be found interesting in this connexion. Of 
the various books published as the result of travels and giving accounts 
of the life of the steppes, mention may especially be made of Prejevalski, 
Wissenschaftliche Resultate der nach Centralasien unternoinmenen Reisen 
(Leipzig, 1889). See also the books mentioned at the end of chapter iv. 



CHAPTER IV 
MOUNTAIN FAUNAS 

The animals of mountain and plateau regions show 
some interesting conditions which make it worth while 
to consider them separately. Taking mountains first, 
we may note that elevated ranges may be divided into 
three regions, each of which presents pecuhar biological 
features. The lowest region is usually clad in forests, 
conifers predominating as we ascend. At a point which 
varies with the exposure, the slope, and other factors, 
even on a single mountain, tree growth ceases, and there 
comes a zone with steppe characters. The width of 
this band and its nature vary greatly. In e. g. the 
mountain regions of Europe, it is characterized by the 
growth of relatively small herbaceous plants, often with 
large and gorgeously coloured flowers, but with tufted 
leaves and other indications of checked vegetative 
growth. Many of these plants reappear in the Arctic 
tundra, but the fact that they are specially abundant 
in the Alps has led to them being called Alpine plants, 
whether they occur in the Alps proper, on the hills of 
Scotland or Norway, in the Himalayas, or in the Cau- 
casus. 

In tropical regions, e. g. in Africa, this steppe area 
with its Alpine plants is replaced by a band where the 
plants show desert characters ; the Lobehas, Senecios, 
and tree-heaths of the upper zone of Ruwenzori and 
Mount Kenya form good examples. In all regions where 
the mountains attain sufficient elevation, above the 
steppe or desert zone comes that of eternal snow, where 



MOUNTAIN FAUNAS 73 

the exposed rocks arc at most scantily clad in mosses 
and lichens. 

Without discussing in detail the characters of moun- 
tain climates, we may note that it seems probable that 
the upper limit of the forest corresponds roughly to 
the zone of maximum precipitation. In ascending 
a mountain the rainfall increases up to a certain point, 
beyond which it begins to diminish. With certain 
modifications, due to inversions, &c., the temperature 
diminishes steadily as we ascend. The relatively 
narrow alpine zone on, e.g., the Alps is due to the fact 
that the vertical distance between the zone of maxi- 
mum precipitation and the snow-line is short. In 
tropical regions the snow-line is pushed far upwards, 
much above the zone of maximum precipitation, and 
the wide interval thus produced between the forest and 
the snow allows for the development of a broad band 
of gradually increasing aridity, where the surface is 
clad in plants of definitely drought-resisting type, the 
low temperature increasing the need for xerophytic 
characters by diminishing the power of absorbing 
water. 

Plateau regions, such as the great plateau of Tibet 
and the far less extensive plateau of Spain, may be said 
to correspond to the steppe zone on an ordinary moun- 
tain. Plateaux of great altitude and great horizontal 
extension tend to show some of the characters of a cold 
desert, thus giving us the special conditions which reign 
in Tibet, but the conditions tend to be less extreme 
than in small and isolated areas of great elevation. 
Plateaux differ from other steppes or deserts in the 
peculiar nature of the relief, which demands special 
agility upon the part of the animals inhabiting them, 
but gives to those possessing such agility a certain 



74 



MOUNTAIN FAUNAS 



security, due to the rugged nature of the surface. 
Further, the pecuHar cHmatic conditions, together 
probably with the rapidity of mechanical erosion, 
promote the growth, in certain localities at least, of 




Fig. 11. A Swiss Alp. The absence of trees, the presence of a close 
short turf and of low bushes (mostly berry-bearing), are very charac- 
teristic of the upper regions of the Alps as well as of many other 
mountain and plateau regions. The richness of the pasture is suggested 
by the number of cows 



particularly nourishing fodder plants. A large part 
of the pastoral industry of Switzerland is due to the 
pasturage obtainable on the high mountain shelves 
or alps. In Tibet, though wild herbivores exist in 
flocks of thousands, according to some observers, yet 
there is pasturage enough to spare to feed the domes- 
ticated animals upon which the community largely 
depends. 



MOUNTAIN FAUNAS 75 

The relatively rich pasturage, and the relative 
security, account for the fact that mountains and 
plateaux have a considerable number of peculiar herbi- 
vores, especially ungulates. The ungulates of mountains 
belong to more than one group, but in the Old World 
at least the two genera of sheep (Ovis) and goat (Capra), 
which appeared late in geological time, include animals 
which are especially adapted for mountainous districts. 
Just as deer are typically forest animals, and antelopes 
typically steppe or savana animals, so sheep and goats 
are the typical inhabitants of elevated regions. In the 
case of sheep, at least, domestication has produced so 
many changes in character, that it is somewhat difficult 
to realize the extraordinary agility of the wild animals, 
and their other special adaptations to Hfe in mountainous 
and elevated regions. The thick coat protects them 
against cold, and the fact that the young — necessarily 
few in number in animals with such a habitat — are 
able to follow the mother anywhere within a very 
short time after birth is an important adaptive char- 
acter. Like steppe animals in general, wild sheep are 
social, and Kke many such animals they seem mostly 
to appoint sentinels while feeding. Their powers of 
leaping are very great, and they seem able to scale 
apparently inaccessible chffs. 

While wild sheep, like domesticated forms, chiefly 
graze upon the ground, the equally agile goats depend 
largely upon the shoots, leaves, and twigs of bushes 
and small trees, and as the trees in their native habitats 
are mostly xerophytic, it is noticeable that the goats 
have very catholic tastes, not disdaining the resinous, 
hairy, or spiny plants native to high steppes. From 
the difference in diet the goats usually occupy ground 
which is more scarped and rocky than that favoured 



76 MOUNTAIN FAUNAS 

by sheep, and they have apparently even greater 
powers of chmbing and leaping. 

As will be explained later, other types of ungulates 
also show adaptations to mountain life, especially in 
those regions which have no wild goats or sheep. Just 
as the two latter types of animals are of relatively 
recent origin, so it is probable are the adaptations to 
mountain life shown by other mountain ungulates. 
Indeed the fleeing to the mountains appears to be the 
latest phase in the long struggle between herbivores 
and carnivores. There is evidence that the herbivores 
acquired swiftness as the carnivores acquired intelli- 
gence and strength. As a general rule the latter seek 
to capture their prey by ruse rather than by direct 
pursuit, and in the open steppes and plains their task 
is relatively easy. To escape them, apparently, no less 
than to utilize the rich mountain pastures, some herbi- 
vores sought the heights, and there the carnivores can 
hardly be said to have followed them, there being few 
large flesh-eaters at great elevations. Indeed the chief 
flesh-eating animals of the mountain ranges of the 
globe are the vultures and their allies, always con- 
spicuous in such regions. 

For convenience' sake we shall take a rapid syste- 
matic survey of the animal kingdom in studying moun- 
tain animals, but it may be noted first that as forest, 
steppe, and tundra are all represented on mountains, 
it is natural that animals from all these regions should 
occur there. 

For example, in the Himalayas we find that those 
truly arboreal animals, the Primates or monkeys, are 
represented high up in the region of coniferous forests, 
where, doubtless, hke the ungulates, they find relative 
security from the great carnivores. The characteristic 



MOUNTAIN FAUNAS 77 

monkey of the Himalayas is one of the langurs, a group 
of slender-limbed, leaf-eating forms widely distributed 
over South-eastern Asia. The particular species is 
Semnopithecus schistaceus, and the animal occurs at 
heights up to 12,000 feet. All who have seen it in 
its native home speak of the peculiar effect of the 
animal among the snow-covered pines and deodars 
there, and the number of forms found on the lower 
ground in India and the adjacent region proves that 
the acquisition of the mountain habitat in this case 
must be recent. The Himalayan form is very closely 
related to the common sacred monkey of India, and 
while sharing with its allies the usual adaptations to 
arboreal life — to be described later — it does not seem 
to show any special fitness for mountain life. Better 
adapted for life at high elevations is the Tibetan langur 
(S. roxellanae), which lives in the forested regions of the 
east of Tibet, especially in the vicinity of Lake Kuku 
Nor, and also extends into China. It is found at 
elevations of over 10,000 feet, and migrates to some 
extent according to the seasons, but never descends to 
the region of cultivated land, the district plundered 
so frequently by the low ground forms. The Tibetan 
langur is somewhat stouter in build and shorter in the 
limbs than the other forms, and has a curious tip- 
tilted nose, whose use is unknown, unless it has any- 
thing to do with facilitating respiration at these high 
altitudes. The hair is very long, and the skin is greatly 
prized by the Chinese on this account. The animal is 
stated to live chiefly on ' fruits ', but no doubt the 
seeds of the mountain trees are also important. As 
the other monkeys of China are species of Macacus, 
there can be no doubt that the Tibetan form has found 
its way into China from the south, through the moun- 



78 MOUNTAIN FAUNAS 

tain barrier. Its presence is thus an indication that 
mountains do not necessarily form a barrier to dis- 
tribution, even to animals reputed to be so sensitive to 
cold as monkeys. 

The macaques also include one moimtain form, 
Macacus tibetanus, which seems to occur in much the 
same region as the Tibetan langur, and also extends 
into China proper, in Sechwan and the south of Kansu. 
The narrow and broken mountain chains of this region, 
according to recent observers, have a damp chmate, 
quite dififerent from that of Tibet proper, and mto the 
valleys the monsoon forest insinuates itself, taking 
with it part of its characteristic fauna, notably the 
two monkeys named. The macaques differ from the 
langurs in their diet, for they eat insects and other 
forms of animal food in addition to fruits and seeds. 
As this food is much more portable than leaves, they 
have cheek-pouches in which it may be stored, these 
being absent in the langurs, which have large saccu- 
lated stomachs, comparable to the stomachs of some 
ungulates. 

The Himalayan and Tibetan langurs and the Tibetan 
macaque appear to exhaust the members of the Primates 
which haunt mountains. None of the New World forms 
seem to be specially fitted for life at high altitudes^ 
and though some of the African baboons inhabit rocky 
regions at some elevation, none seem to be pecuHar to 
high mountains or plateaux. 

The insectivores have various mountain representa- 
tives, some showing peculiarities of distribution. The 
Alpine shrew {Sorex alfinus) inhabits the upper parts 
of the lofty mountain regions of Central Europe ; the 
Himalayan swimming shrew {Chimarrogale himalayica) 
inhabits the lower slopes of the Himalayas, where it 



MOUNTAIN FAUNAS 79 

haunts streams and. feeds upon aquatic insects and 
their larvae, tadpoles, and small fish ; the desman 
{Myogale pyrenaica) of the Pyrenees inhabits the banks 
of streams in that mountain range, and spends a con- 
siderable part of its time in the water ; the Tibetan 
mole-shrew {Uropsilus soricipes) is a small cursorial 
animal, seeming to be intermediate between moles and 
shrews. The insectivores are, however, losers in the 
battle of life, and there is nothing remarkable in the 
fact that peculiar forms are found in mountain ranges, 
when we remember the shifts the members of the group 
have been put to in order to survive in a world where 
the mammals as a whole have better developed brains 
and greater differentiation of structure than they can 
boast of. 

Carnivores, as we have seen, are not very abundant. 
The forms which inhabit the neighbouring regions — 
forest or steppe — may extend also into the mountain 
regions, but peculiar forms are not numerous, the bear 
alliance being that with most mountain representatives. 

Of the cats the most characteristically mountain 
form is the ounce or snow leopard {Felis uncia, Fig. 12), 
a beautiful animal with very thick fur, greyish above, 
with black spots, and pure white below. In Ladak it 
is said to ascend as high as 18,000 feet in summer time, 
and not to descend lower than 9,000 feet in winter. It 
attacks wild goats and sheep, and also rodents, but its 
habits are not well known. In the New World the 
puma {Felis concolor, Fig. 26), though not specifically a 
mountain animal, attains a considerable height in 
the Rocky Mountains, and is stated to prey upon the 
Bighorn sheep. 

Of other cat-like carnivores extending into moun- 
tainous regions, we may note that the lynx of the 



80 MOUNTAIN FAUNAS 

northern forests extends in a special variety, or species 
{Lynx isabellina), into the plateau of Tibet, where it 
shows some adaptations to rocky and barren country, 
instead of to forest-covered ground. The Indian wild 
dog {Canis deccanensis) shows a similar extension of 
habitat from the forests of India into the wastes of 
Tibet. It is a social animal, the packs hunting down 
wild sheep, antelopes, &c. In the Himalayas and Tibet 
also, the common fox is replaced by a variety with 
thick fur and a very large brush. 

We come next to the bears, of which several occur in 
mountain regions. Thus the Himalayas and Tibet have 
special varieties of the brown bear, which, like bears in 
general, is very resistant to cold on account of the 
thickness of its coat. Its very indiscriminate appetite 
also makes it possible for it to exist on many different 
kinds of ground. The Atlas Mountains have a closely 
related form, and in the Rocky Mountains the large 
and powerful grizzly bear {Ursus horribilis) occurs at 
considerable elevations, though also descending to the 
plain. In the wooded regions of the Himalayas occurs 
the black bear (Ursus torquatus), chiefly a vegetable 
feeder and an excellent climber, which in the Hima- 
layas does not voluntarily quit the forest. It is not 
known in Tibet, and differs from most bears in the 
short and thin coat. The necessary resistance to cold 
is apparently obtained by the great oiliness of the skin, 
especially in autumn, when the animal is very fat — 
a means of providing for the winter time of scarcity. 
The Andes of South America contain another mountain 
bear, in the shape of the spectacled bear {Ursus 
ornatus). Africa south of the Sahara has no bear. 

That forested region of Eastern Tibet which lodges 
the Tibetan macaque and the Tibetan langur has still 




as 






fs* 



♦^S' 







Ph 



j^id^ai 



MOUNTAIN FAUNAS 81 

another remarkable form in the parti-coloured bear 
{Aduropiis melanoleucus) . It is curiously marked in black 
and white, has a very thick close fur, and enormously 
powerful jaws. The latter feature is remarkable in view 
of the fact that the animal seems to be purely vegetarian 
in tastes. It is said to inhabit the bamboo thickets which 
in this region ascend the damp valleys up to a height 
of nearly 10,000 feet. The young shoots of bamboos 
form the greater part of its food, and it is stated to be 
an excellent climber. 

A curious little animal called the panda {Aelurus 
fulgens), once beheved to be related to Aeluropus, occurs 
at considerable elevations in the south-eastern Himalayas 
and feeds chiefly on vegetable matter, especially bamboo 
shoots. The panda is an arboreal animal, somewhat 
fox-like in appearance, and is now believed to be most 
nearly related to the carnivorous raccoons of America, 
which are forest animals, sometimes, as in the case of 
the forms called coatis (Nasua), ascending to a consider- 
able elevation above sea-level. 

The comparative rarity of large and fierce carnivores 
helps to explain, as we have seen, the abimdance of 
ungulates in mountain regions. Beginning with the 
cattle, we may note that just as one form — the musk- 
ox — is admirably adapted for life on the timdra, so 
another — the yak of Tibet — is perfectly fitted for life 
at a great elevation. This animal, the Bos grunniens 
of zoologists, is characterized by its long hair, and by 
its great agihty and hardiness. It ascends to a height 
of 20,000 feet above sea-level, and while impatient of 
heat, is extraordinarily resistant to cold, and is capable 
of thriving on the coarsest of herbage. As is well known, 
the animal is used as a beast of burden in Tibet, on 
account of its great endurance. Travellers have often 

1404 V 



82 MOUNTAIN FAUNAS 

described the way in which the animals push their way 
through snow, or across glaciers, or through icy glacial 
torrents. They present a remarkable instance of 
adaptation to very unfavourable conditions, but in this 
connexion it is important to remember the great extent 
of the plateau of Tibet, and its great uniformity. 

The yak is the only member of the cattle group with 
special adaptations to mountain life. Passing to the 
sheep we find that there are eleven well-defined wild 
species. Of these, eight inhabit various mountain chains 
and plateaux in Asia, one, the Indian urial, extending 
to relatively low ground in the Punjab and Sind ; one 
form is found in the Rocky Mountains, but this, the 
Bighorn, is so closely related to the wild sheep of 
Kamchatka as to suggest a former land connexion 
across the Bering Strait. Of the remaining two species, 
one, the mouflon, occurs in mountain regions in Sardinia 
and Corsica, and the other, the Barbary sheep, is found 
on the southern slopes of the Atlas Mountains in Africa. 
We are thus justified not only in saying that sheep are 
definitely mountain animals, but also that the home of 
the genus is the mountainous regions of Central Asia, 
only the urial extending south of the Himalayas, The 
habits of all are generally similar, and have been 
already alluded to. To the preceding description we 
may add a brief note on the wild sheep called argali, of 
which one form {Ovis ammon) is found at moderate 
elevations in Mongolia, while the other {Ovis hodgsoni) 
occurs at great heights on the Tibetan plateau. Both 
are large animals, reaching the size of a small donkey, 
and having short and close hair. The food consists of 
grass, mingled in winter with mosses and lichens, and, 
like the reindeer of the tundra, the animals in winter 
seek exposed positions where the wind sweeps away 




Fig. 14. The Alaskan Wild Sheep (Ovis dalli), a form closely related both 
to the American Bighorn and to the wild sheep of Kamchatka. (Photo by 
the Biological Survey, U.S.A.) 




t^^ldk^PSM^ --T!^:>y^-^ Z -Tli^r-ai-".- 



FiG. 15. A young Takin in captivity in Tibet. Tlic iuryu lateral hoofs are 
a special feature. ( Photo by Ca/pt. F. M. Bailey. ) 




Fig. 16. Half-wild Kiang, near Gyantse, Tibet. The type of country is very 
characteristic. {Photo by Ca/pt. F. M. Bailey.) 



MOUNTAIN FAUNAS 83 

the snow. In the male the horns are large and massive, 
while the female has smaller and thinner structures. 
Like all their allies, the animals are very wary and 
agile. 

The goats are mostly distinguished from the sheep 
by the presence of a beard on the chin, and by the 
strong odour of the males. They also are mountain 
animals, their distribution showing a remarkable 
analogy to that of the sheep, except that there is no 
true American goat. Some ten species of wild goat 
occur in the Old World, and of these, two species, the 
ibex of Abyssinia and the Arabian wild goat, which 
extends into Upper Egypt, enter Africa. The remainder 
occur in the mountain regions of Europe or of Central 
Asia. In Europe there is a curious tendency for the 
(isolated) mountain chains to have peculiar species of 
goats. Thus there is a Spanish wild goat, sometimes 
called an ibex ; the Alpine ibex, now exterminated as 
a wild animal, is peculiar to that chain, and no less 
than three species of wild goats inhabit the Caucasus, 
Of the Asiatic species the most attractive is the markhor 
(Capra falconeri) of the Himalayas, with long spirally 
twisted horns in the male, and fringes of hair on the 
chest and shoulders in addition to the beard. Closely 
related to the goats are a series of smaller genera, such 
as Hemitragus, including the tahr of the Himalayas, 
and another species found in the Nilgiri Hills of Southern 
India, there being thus a curious separation between the 
range of the two species. The gorals (Cemas) and 
serows (Nemorhoedus) are Himalayan and Tibetan 
forms, which seem to connect the goats with the 
antelopes, while the takin of Eastern Tibet is a large 
form with curiously shaped horns. The interest of 
these genera is merely that they emphasize what has 

F 2 



84 MOUNTAIN FAUNAS 

been said already as to the number of kinds of ungulates 
found in Tibet, the Himalayas, and adjacent regions. 

Though America has no true goat, there occurs in 
the Rocky Mountains a white ungulate, about the size 
of a large sheep, and apparently related to the serow, 
often called the Rocky Mountain goat. Its hair is very 
long, and the animal seems to be very resistant to cold, 
spending its time near the upper limit of the forest, 
although it also descends at times to sea-level. Nearer 
the antelopes than the goats is the chamois {Rwpi- 
capra tragus), a rather clumsily built animal with short 
hooked horns, stumpy tail, and feet especially fitted 
for scrambling about rocks. It is widely but discon- 
tinuously distributed over the mountain regions of 
Europe, but is found fossil on the low ground also. 

Of the true antelopes many of the gazelles ascend to 
considerable elevations, notably the Tibetan gazelle 
{Gazella picticaudata), which ranges up to 18,000 feet, 
and is less shy than most gazelles. Tibet has also 
a peculiar antelope, the chiru {Pantholops hodgsoni), an 
animal in which the male has a curious swollen nose 
and long horns. This form occurs at the same heights 
as the gazelle, sometimes in very large herds. In the 
distended nose it somewhat resembles the saiga of the 
Siberian steppes. 

Of the vast number of African antelopes some 
frequent hill regions, notably the rhebok {Pelea cap- 
reola) of the south and east, which has the habits of 
a chamois. Another agile and chamois-like African 
form is the klipspringer [Oreotragus saltator), found at 
heights up to 8,000 or 9,000 feet in Abyssinia, and 
having very small feet, which apparently give it 
great sureness on the rocks. Both its Dutch and Latin 
names refer to its jumping powers. 




Fig. 17. The Bharal or Burhel, one of the wild sheep of Tibet {Ovis nahura). 
Note the curious markings on the legs. (Photo by Capt. F. M. Bailey.) 




Fig. 18. The Serow of Tibet. (Photo by Capt. F. M. Bailey.) 




Fig. 19. Musk-deer. Note the large lateral hoofs, the coarse coat, the promment 
canines of the male. {From a specimen in the Royal Scottish Museum.) 



MOUNTAIN FAUNAS 85 

Of the deer we may note that the somewhat primitive 
musk-deer {3Ioschus moschiferus) occurs at consider- 
able elevations in the Himalayas, being usually found 
in the birch forest above the zone of pines. From the 
Himalayas the musk-deer extends northwards into 
Central Asia and Siberia. It has imusually large lateral 
hoofs, which apparently assist it in obtaining foothold 
on hard snow or rocky ground, and feeds largely on 
twigs and buds. The coat is thick, the hair being long 
and coarse, and giving much protection against cold. 
The kiang (p. 60) occurs in Tibet as well as in the 
Mongolian steppe. 

As already explained. South America is singularly 
poor in ungulates, but in the Andes two members of 
the camel family occur, the guanaco and the vicuna. 
These animals have very soft feet, and though they 
ascend to the highest ridges, they avoid equally rocky 
regions and snow and ice. At the wet season they go 
high up the mountain sides, but when the vegetation 
there dries up at the approach of the hot season they 
descend to valleys watered by springs or perennial 
streams. The long coat affords protection against cold, 
and the animals seem never to descend below 6,000 
or 7,000 feet in the hotter parts of their range. 
That this is partly due to intolerance of heat seems 
indicated by the fact that the guanacos come down to 
sea-level in Patagonia. The vicuna has a more limited 
extension, being confined to the district between 
Southern Ecuador and Central Bolivia. One of the 
American tapirs also {Tapiriis roulini), ascends to an 
elevation of 7,000 to 8,000 feet above sea-level in 
Ecuador and Colombia, without, apparently, showing 
any special adaptations to mountain life. In the 
Andes of Chile and Ecuador also occur the tiny deer of 
the genus Pudua, which are no bigger than hares. 



86 MOUNTAIN FAUNAS 

The very aberrant and somewhat primitive ungulates 
called hyraces (Procavia) show some interesting features 
as regards adaptation to mountain life. All are small 
animals, very like rodents in appearance and habits, 
and resembling most of those animals also in their 
helplessness and want of swiftness. WTien small herbi- 
vores cannot defend themselves actively, cannot escape 
by flight, and cannot burrow, only two possible means 
of escaping their enemies remain. These are to haunt 
rocky country where the fallen stones and blocks offer 
natural shelter, or to seek the trees. Both methods are 
adopted by the hyraces. The common hyrax of Syria 
gets its name of rock coney from its habit of frequent- 
ing rocks, where it pops in and out of the crevices as 
a rabbit pops in and out of its burrow. As rocky 
country is more frequent in mountainous regions than 
elsewhere, we find that the ground hyraces usually 
occur in elevated districts, though frequenting suitable 
ground elsewhere in addition. They have four well- 
developed toes on the fore foot, and three on the hind, 
and the size of the feet, with the spreading toes, enables 
them to scramble about rocks very easily. The tree 
hyraces, without any notable difference in structure, 
show a marked difference in habit in that they live 
entirely among trees, in which they feed, breed, and 
sleep. Being relatively hardy they occur at great 
elevations, e. g. at from 7,000 to 11,000 feet in the forests 
of Kilimanjaro. In both the ground and tree forms, 
those attaining a great elevation seem to differ chiefly 
in their thicker coats. AU the hyraces are confined to 
Africa and the adjacent regions, e.g. Syria and Arabia. 

Among the true rodents we find, as already indicated, 
many mountain species. In the consideration of steppe 
faunas something was said of marmots (Arctomys), 



MOUNTAIN FAUNAS 87 

and as these are typical denizens of cold steppes, it is 
natural that they should occur also in the steppe region 
of lofty mountain chains. In Europe the Alpine marmot 
is fou/id in the Alps, the Pyrenees, and the Caucasus, 
though it once occurred on the low ground also. In 
Central Asia many kinds of marmots occur, though 
none extend to the south of the Himalayas. The 
Himalayan marmot, allied to the bobac of the steppes, 
is limited to the region above the tree limit, that is, to 
the barren wastes which most nearly resemble the home 
of the bobac, the usual elevation being 12,000 to 13,000 
feet. In North America we have similarly a Rocky 
Mountain marmot, resembling in habits the Alpine form. 

The voles (Arvicola) are well represented in mountain 
regions, the genus showing a remarkable tendency to 
run into varieties, or species, in particular localities. 
Thus in the Alps and Pyrenees there occurs the very 
curious Alpine or snow vole {A. nivalis), which is some- 
times pure white, but is structurally very near the 
continental field vole and the bank vole. It differs 
notably from these forms in its habits, for it lives high 
up the mountains, even above the snow-line. It has 
been found on the Finsteraarhom at a height of 12,000 
feet, but on account of its habits is rarely seen. It 
appears to live actually beneath the snow, making 
runs beneath it after the fashion of the Arctic lemming, 
in its search for vegetation. Other mountain species 
occur in the Himalayas and Tibet. 

South America, with its paucity of ungulates, has 
a considerable number of peculiar mountain rodents. 
Thus the common chinchilla {Chinchilla lanigera), with 
its soft thick fur, inhabits the higher parts of the Andes, 
living in rocky ground, and displaying marvellous 
agility. A larger form {Lagidium cuvieri) inhabits the 



88 MOUNTAIN FAUNAS 

same regions, and has similar habits. The pacas of the 
Brazihan woods are represented on the mountains by 
a smaller type {Coelogenys taczanoivskii). Some of the 
cavies also ascend to momitain regions, notably the 
Bolivian cavy {Cavia holivensis), which lives in large 
societies in the upper part of the Andes, tunnelling the 
ground in all directions with its burrows. 

As to the hare-like rodents, we have already noted 
that the picas or tailless hares occur at great elevations 
in the Himalayas in addition to frequenting the Siberian 
steppes, thus illustrating the same conditions as the 
marmots. The mountain hare of Europe is closely 
related to the Arctic hare already discussed (p. 22), 
Tibet has several species of hares, the most interesting 
being Lepus hypsibiiLS, which does not descend below 
14,000 or 15,000 feet. 

Among birds we find that many kinds of birds of 
prey haunt mountains, though they are not necessarily 
confined to them. Of wide distribution is the laem- 
mergeier {Gypaetus harbatus), found in the mountain 
ranges of Europe, North Africa, and Central Asia, 
which apparently feeds largely on carrion and animals 
not killed by itself. The even more widely distributed 
Golden Eagle {Aquila chrysaetus), on the other hand, 
kills its own prey, which consists of rodents, the young 
of ungulates and game birds. Other forms which may 
be mentioned are Bonelli's hawk-eagle {Nisaetus fascia- 
tus), found in the Alps as well as in Asia and North 
Africa, and the magnificent condor {Sarcorhampus 
gryphus) oi the Andes of South America. In tropical 
countries some of the parrots range up moimtain sides, 
and in this connexion it is curious to note that the 
New Zealand kea {Nestor notabilis), which inhabits 
barren mountain sides, has become virtually a bird of 



MOUNTAIN FAUNAS 89 

prey since the introduction of sheep into that area. At 
first confining itself to dead sheep, the bird is stated now 
to kill living animals with blows of its powerful beak. 

As is to be expected from the conditions, game 
birds are frequent on mountains. Thus in the Alps we 
find the ptarmigan, and it is also found on the other 
mountain ranges of Central Europe, on most of which 
the black grouse or capercaillie is found. In the 
mountain ranges of South Europe generally the Greek 
partridge {Caccabis saxatilis) lives. To the pheasant 
family belong the snow-partridge {Lerwa nivicola) of 
the Upper Himalayas, and the very large snow-cock 
{Tetraogallus Jiimalayensis) of the Himalayas and Tibet. 
Other examples might be given, but these sufficiently 
indicate the two essential facts — that some of the game 
birds of the tundra and pine forests extend to the 
mountain ranges of the interior, and that the great 
elevated area in Central Asia has its peculiar game birds, 
as it has its peculiar ungulates and its peculiar rodents. 

In regard to other t3rpes of birds, a few words may 
suffice. In the Alps the commonest member of the 
crow family is the Alpine chough {Graculus alpinus), 
smaller than the common form, and having a yellow 
instead of a red beak. In the pine forest of mountains, 
especially in the Tyrol, occurs the citril finch {Chryso- 
mitris citrinella), while high up on the Alps is found 
the beautiful black and white snow-finch {Monti- 
fringilla nivalis), allied forms of which also occur on 
the mountains of Central Asia. Both in the Alps and 
in Central Asia is found the curious wall-creeper {Ticho- 
droma muraria), which lives on insects and spiders, 
found by probing in rocky- crevices. In shape and 
flight this bird has a remarkable resemblance to a large 
butterfly, as it hovers over the rocks, using its long 



90 MOUNTAIN FAUNAS 

sharp bill to pick out its prey just as a butterfly uses 
its proboscis to suck up nectar. In the Alps another 
frequent bird is the rock-thrush {Monticola saxatilis), 
a brightly coloured bird, extending up into the barren 
regions of the mountain sides. In the Alps and Pyre- 
nees also the Alpine accentor {Accentor collaris) is 
common. With the exception of the hedge-sparrow, 
most of the accentors are mountain-haunting birds, 
having strong feet and legs, which fit them for pro- 
gression over rough ground. Of the summer visitors to 
the Alps, we may note the Alpine swift {Micro'pus 
melba), which is larger than the common form. 

Reptiles do not appear to show any special adapta- 
tions to mountain life. It is remarkable that the 
common viviparous lizard {Lacerta vivipara) ascends 
to a. height of 10,000 feet in the Alps, but then this 
hardy animal also extends into Siberia. The common 
viper {Pelias herus) also occurs in the Alps, though not at 
such a great elevation, and it has a similarly wide range. 

As regards amphibians, there is some evidence that 
the mountain habitat tends to produce darkening of 
the colour. Thus the common frog {Rana temporaria) 
occurs in the higher parts of the Alps in a dark-coloured 
variety, and the same thing is said to be true of the 
common toad {Bufo vulgaris). Similarly the Alpine 
salamander {Salamandra atra) is black in colour, and 
unspotted, thus differing markedly in colour from its 
allies. This form shows a peculiar adaptation to life 
at considerable elevations, in that it only produces two 
young at a time, and these pass through the gilled stage 
within the body of the mother, so that at birth they 
are lung-breathers like the parents, and not gill-bearing 
tadpoles. As the animal ascends to an elevation of 
9,000 feet, it is obvious that ice-free water for the 



MOUNTAIN FAUNAS 91 

relatively long period of larval development would not 
be easy to find — hence the adaptation described. In 
mountain streams in China and Japan occurs Siebold's 
giant salamander {Cryptobranchus maximus), reaching 
a length of over five feet. 

Relatively few species of fish occur in mountain 
streams, doubtless on account of the coldness of the 

water. 

In regard to the lower forms of life we need only note 
that with the great development of flowering plants 
during the short period of summer in most mountain 
regions, we have a great development of insects, 
especially butterflies. There is a marked general 
resemblance between the insects of mountains and of 
polar regions, due doubtless partly to the similar 
physical conditions which prevail in the two regions. 

References. Kobelt's book has a good chapter on mountain animals, 
and Tschudi's Thierleben der Alpenwelt (ninth edition, Leipzig, 1872) 
should also be consulted. An account of Alpine animals will also be 
found in Anderegg's Schweizerische Alpwirtschaft (Berne, 1899). There 
are a number of works on travel in Tibet and the neighbouring regions 
which give accounts of various of the characteristic animals. Among 
these may be mentioned : Demidoff's After Wild Sheep in the Altai 
(London, 1900) ; Adventure, Sport, and Travel on the Tibetan Steppes, 
by W. N. Fergusson (London, 1911) ; P. T. Etherton's Across the Roof 
of the World (London, 1911). 



CHAPTER V 

THE FAUNA OF THE TROPICAL FOREST 

Just as the tropical forest as contrasted with the 
temperate is remarkable for its wealth of species of 
trees and for the luxuriance of its undergrowth, so its 
fauna is remarkable for the number of special tjrpes. 
Adaptations to life in the tropical forest occur in almost 
all groups of animals, and some orders, like the Primates 
among mammals, are, roughly speaking, fitted for this 
habitat alone, for relatively few of their members occur 
outside this region. 

We may begin by a few words upon the special con- 
ditions which reign here. To begin with, food is abun- 
dant all the year round, for there is no seasonal check 
to vegetation such as occurs in temperate climates. 
The absence of seasons, in the sense in which they 
occur in higher latitudes, makes possible the occur- 
rence of many fruit-eating animals, for fruits occur at 
all seasons. Thus the anthropoid apes are fruit-eaters ; 
the fruit-bats have the same diet, as the name indicates ; 
parrots eat seeds and fruits, and so on. For such 
forms life in colder climates is impossible. 

The constantly high temperature, at least during the 
day, makes a warm coat unnecessary, so that animals 
producing valuable furs are relatively rare. The same 
condition makes reptilian life abundant, for the heat 
of the sun is available to hatch the eggs. The high 
temperature also results in abundance of insects, which 
again feed many other animals. 

As the tropical forest is characterized by a very 



FAUNA OF THE TROPICAL FOREST 93 

luxuriant undergrowth, and by great density, we find 
not a few arboreal forms which never voluntarily put 
foot to the ground. This is true of the South American 
sloths, whose feet are quite unfitted for terrestrial pro- 
gression, also of some of the monkeys, of forms like the 
flying lemur, and so forth. Where the forest is less 
dense than usual, such purely arboreal forms must at 
times find it difficult to pass from one tree to another, 
and it is notable that very many different kinds of 
arboreal animals have some form of parachute, giving 
them partial powers of flight, or at least of taking long 
leaps. Thus we have flying frogs (Rhacophorus) ; a fly- 
ing lizard {Draco volans) ; flying phalangers ; African 
flying squirrels, differing in several respects from the 
forms found in temperate climates ; the so-called 
flying lemur, &c. The true lemurs do not possess 
parachutes, but some forms (e. g. Galago) have the 
ankle greatly elongated, which gives them a very frog- 
like appearance, and enables them to leap from one 
tree to another. 

As regards the structure of the feet, two conditions 
occur in the more highly specialized forms. Some- 
times, as in the sloths of South America, the fingers 
and toes are converted into hooks, incapable of being 
separated from one another, and having as their sole 
function the suspending of the body from the branches 
of the trees. This condition is suggested also in some 
of the thumbless monkeys, but in general the monkeys 
and their allies, together with some other animals, 
show a character which gives as great security of 
grip, while conducing to greater freedom of movement 
and greater agility. This is the modification of one 
digit on both hands and feet, which is so inserted that 
it can be opposed to each of the other digits, producing 



94 THE FAUNA OF 

the condition described as the opposable thumb and 
great toe. At the same time the extremities of the 
digits tend to be flattened, giving more gripping power, 
and with the flattening of the finger-tips a nail tends 
to replace a claw. This condition is only gradually 
acquired in the Primates, the lower forms having 
pointed fingers, with nails instead of claws. As already 
suggested also, the hand in certain Primates tends to 
become hook-like, the thumb being absent or minute. 
Only in man among the Primates is the great toe not 
opposable. 

But this condition of one (or more) digit being 
opposable to the other is not confined to the Primates. 
In the opossums and phalangers, primitive mammals 
whose young are bom in a very undeveloped state, the 
great toe is also opposable. Again, in parrots among 
birds, and the chameleon among lizards, a gripping 
hand and foot is produced by certain digits being 
opposable to the others. 

Still another adaptation to arboreal life is seen in 
the prehensile tail. This also occurs in widely separ- 
ated groups. We find it in the chameleon, in the New 
World monkeys, in opossums, in some of the South 
American ant-eaters, in the South American tree-por- 
cupines, in the kinkajou, and so forth. Like the hook- 
shaped hand it tends rather to occur in relatively sluggish 
forms than in those whose agility is sufficient to enable 
them to recover easily from a false movement. Thus 
Brehm notes that the * five-handed ' New World 
monkeys are not nearly such good climbers as the 
four-handed monkeys of the Old World, which never 
have prehensile tails. 

Some minor adaptations to the arboreal life may 
next be touched upon. As great freedom of movement 



THE TROPICAL FOREST 95 

of the limbs is necessary, we note that these are not 
tied down to the body by skin, as in most quadrupeds. 
A comparison of such animals as dog or cat with 
monkey or man will make this point clear. Again, as 
the arms are of very great importance in arboreal 
animals, we find that they are proportionately very- 
long. In the sloth, in the monkeys and lemurs, this is 
very noticeable. With the loss of other arboreal charac- 
ters man has also lost his long arms, these being pro- 
portionately very much shorter than in the apes. 

Another common feature of arboreal mammals is 
the presence of collar-bones, which tend to be lost in 
quadrupeds. This gives such mammals a charac- 
teristically broad chest, easily seen on comparing the 
position of the fore-limbs in, e.g. a sheep, and in a 
monkey. It is the presence of the clavicle which per- 
mits of the upward movement of the arm, so necessary 
in climbing, a movement impossible to pure quadru- 
peds like antelopes and deer. Again, in quadrupeds, 
and notably in the swift ungulates, the two bones of 
the forearm and the corresponding bones of the fore- 
leg tend to fuse, in order to give a rigid support to the 
body ; but in most arboreal animals they are separate, 
giving much greater freedom of movement to wrist 
and ankle, but preventing the animals from acquiring 
any great speed on the ground, even when their fingers 
and toes make it possible for them to attempt to run. 

Finally, arboreal forms have often only one or two 
young at a birth, and the mammae are frequently 
pectoral in position, for only thus can the young be 
carried without loss of balance by the mother. 

To this account of the chief peculiarities of arboreal 
animals we may add a few words upon the tropical 
forest considered as a source of food. In the tropical 



96 THE FAUNA OF 

forest there is, as already indicated, no seasonal check 
to vegetation, and therefore no marked variation in 
the amount of vegetable food available. But there is 
much evidence to show that the total amount is less 
than might be expected. The tropical forests of New 
Guinea yield almost no food for man, so that recent 
expeditions have had to import every particle Con- 
sumed, and have at times run almost the same risks 
of starvation as explorers in the tundra, even when 
armed with modern weapons. Elsewhere there are few 
human groups indeed who manage to subsist solely on 
the products of the tropical forest, and those who do, 
e. g. the Congo pygmies and the Phihppine negritos, 
seem to be few in number, and yet to sufifer from chronic 
starvation. They do not reach a high state of civiliza- 
tion. The fact that all the more intelligent of the 
forest animals soon learn to rob man's plantations, or 
to prey upon his flocks and herds, suggests that the 
wild mammals are no better off than forest-dwelling 
man. The reasons why the conditions should be 
relatively unfavourable in the tropical forests are 
perhaps a little obscure, but we note among them that 
the physical conditions most favourable to plant life 
are not those best suited to the mammaUa at least. 
Further, the enormous number of plant species in the 
tropical forest diminishes the chance that a particular 
useful species will occur in numbers. The fact that 
trees of commercial value only occur in isolated speci- 
mens is a great barrier to the exploitation of the tropical 
forest by man, and it has doubtless also its effect on 
the wild animals. If there is one Cembra pine loaded 
with ripe seeds in the taiga, there will almost certainly 
be many in the vicinity ; if the squirrels find one 
hickory tree in the American woods whose nuts are 



THE TROPICAL FOREST 97 

ripe, there will also be many others. On the other hand, 
just as man has to hunt for individual camphor trees 
in the Formosan forests, or for individual rubber trees 
in the Brazilian forest, so must the fruit-eating wild 
mammals hunt through the forest for the scattered 
trees whose fruits supply their hunger. This is perhaps 
part of the reason why the tropical forest seems to the 
explorer to be deprived of animal life save insects and 
reptiles, part of the reason why the forest mammals 
mostly occur in relatively small numbers. 

If we consider in systematic order the groups of 
animals showing adaptation to life in the tropical forest, 
we naturally begin with the Primates, whose members 
display practically all those characters which we have 
described. Their long arms and short legs, their oppos- 
able thumbs and great toes, their strong clavicles, in 
some instances their prehensile tails, their pectoral 
mammae, and the reduction in the number of young 
at a birth — all these fit them for life among the trees. 
On the other hand, their generalized teeth, the number 
of fingers and toes present, the condition of the bones 
of the limbs, and other characters, show their descent 
from relatively primitive ancestors, specialization show- 
ing itself chiefly in brain development, and in the fact 
that the hands are progressively suited for many uses, 
in addition to their prime function as aids in climbing. 

One point of structure is interesting. Most herbi- 
vorous, or partially herbivorous, animals are specially 
exposed to danger when feeding, for large quantities 
of vegetable food must be taken. Many of the ungulates 
have an arrangement whereby the hastily swallowed 
food can be stored within the alimentary canal, careful 
mastication taking place later. In most of the monkeys, 
on the other hand, food can be temporarily stored in 

1404 G 



98 THE FAUNA OF 

cheek-pouches, to be chewed and swallowed later. This 
arrangement is far from universal — ^it is absent in all 
the New World monkeys and in some Old World 
forms, but it is nevertheless common. 

As, with the exception of baboons, and of the Tibetan 
and Himalayan forms already mentioned, all Primates 
are denizens of the tropical forest, it is impossible to 
name all the members of the order here — a few ex- 
amples only can be picked out. 

Apart from man, the highest living forms are the 
anthropoid apes, of which there are four living kinds — 
the gorilla and chimpanzee from West Africa, the orang 
in Sumatra and Borneo, the gibbons from South-East 
Asia. Like man himself, and Uke most Primates except 
the lemurs, the anthropoid apes are diurnal in habit, 
not nocturnal, like many mammals. The gorilla and 
chimpanzee resemble man in the region which they 
inhabit in having dark skins and hair ; the body is of 
course much more hairy than in man. The gorilla, 
which has a very limited distribution, is a dweller in 
dense forest regions, and is an extraordinarily powerful 
animal. It is purely vegetarian and fruit-eating, shar- 
ing a taste for some fruits with the negroes of the 
region, and also consuming some which the negroes do 
not care for. The fact that it robs human plantations 
shows that food is sometimes scarce, even though the 
animals appear to be very few in number. Wild plan- 
tains and ' palm cabbage ' are freely eaten. 

The chimpanzee, which extends into Central Equa- 
torial Africa apparently, at least at times, eats some 
animal food in addition to fruit. 

Very different in appearance from the gorilla and 
chimpanzee is the orang, with its very long arms and 
its covering of long reddish hair. The way in which 




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41. ■»^^ 




Fig. 21. The Margin of the Equatorial Rain-Forest iii ]S'orth Borneo. Where- 
ever this type of forest occurs it shows similar density (see Fig. 22), a fact 
which explains the existence of so many purely arboreal animals (cf. Figs. 23 
and 32) which spend their whole lives among the trees. (Photo by H.M. Lomas.) 




Fig. 22. The Congo Tropical Forest (Belgian Government.) 



THE TROPICAL FOREST 99 

the knee turns outwards makes it even less fitted for 
the upright position than its allies, but the resultant 
inward position of the sole of the foot makes it even 
more skilful in cHmbing. The animals are indeed 
excellent climbers, but are somewhat deliberate in their 
movements. They do not appear to come voluntarily 
to the ground, and are fitted for dense primaeval forests. ' 
The gibbons are very much more active in their move- 
ments ; so active, indeed, as to be able to catch birds on 
the wing. They mingle with their vegetable food a 
considerable amount of animal matter, especially eggs 
and nestling birds. With the other egg-eating animals 
of the tropical forests they have probably been one 
factor in determining the migration of so many birds 
every year to the northern forest, where they can rear 
their young in comparative security. 

The gibbons have even longer arms than the orang, 
but differ in that they can plant the foot flat upon the 
ground, and walk, though not rapidly, in the upright 
position. 

Of other forms we may note that the langurs, already 
mentioned (p. 77), are long-tailed, leaf -eating monkeys, 
widely distributed over South-East Asia. Though 
the arms are relatively short, the animals are exceed- 
ingly agile, making their way through the trees with 
great rapidity. In West Africa the langurs are re- 
placed by thumbless monkeys belonging to the genus 
Colobus, which are also leaf -eaters, and are remarkable 
for their long silky hair. 

West Africa, the region, it will be recollected, where 
the tropical forest is best developed, is also inhabited 
by the monkeys of the genus Cercopithecus, to which 
the monkey usually carried about by organ-grinders 
belongs. All have cheek-pouches, and the diet is very 

G 2 



100 THE FAUNA OF 

varied. In Asia the macaques are similar forms, with 
very large cheek-pouches and a most indiscriminate 
appetite, animal food entering largely into the diet. 
The baboons of Africa are much more widely dis- 
tributed through that continent than most genera of 
monkeys, but this is associated with the fact that they 
are not forest animals in the true sense, being chiefly 
found on rocky ground, and being practically quad- 
rupeds. The shortness of the arms is a drawback in 
climbing, at which they do not appear to be skilful. 

Very different from all the Old World monkeys are 
those which haunt the equatorial forests of Brazil, and 
constitute the Platyrrhine or American forms. All these 
animals are small, none has an opposable thumb, the 
tail is usually prehensile, and the partition between the 
nostrils is broad. Examples are the various kinds of 
capuchins, which have a mixed diet, and share with 
some Old World forms the habit of plundering culti- 
vated land. In the absence of cheek-pouches they carry 
away part of their spoil in their hands or under their 
arms, the arms not being indispensable in climbing, 
which is carried on largely by the tail. The spider mon- 
keys (Ateles) are comparable to the thumbless monkeys 
of Africa in the total absence of the thumb. As their 
name indicates, they have long slender limbs, and are 
very skilful climbers, the long and markedly prehensile 
tail playing a great part in the process. The leaf -eating 
howling monkeys (Mycetes, Fig. 23) may also be named, 
but a considerable number of other genera occur, some 
without prehensile tails. Though characteristic of the 
equatorial forests, these New World monkeys extend 
northwards into Southern Mexico, and southwards to 
lat. 30^ S. 

Of much more limited distribution are the little 




Fig. 23. The Red Howling Monkey, an American form with a prehensile tail. 
{From a specimen in the Royal Scottish Museum.) 




fSH 



THE TROPICAL FOREST 101 

marmosets, which occur only in the tropical forests of 
South and Central America. These animals are very 
squirrel-like in appearance, and show much fewer 
adaptations to the arboreal life than the higher Pri- 
mates, in spite of the fact that they spend their lives 
among the trees. Thus the fingers and toes, except the 
great toe, have pointed claws instead of nails, the hind 
legs are larger and better developed than the front 
ones, and the great toe is very small. The tail is non- 
prehensile. In the absence of the special adaptations 
shown by their allies, the animals climb like squirrels 
rather than like monkeys — that is, they do not grip 
the branches and swing freely from one to another, 
but stick in their claws and climb along the branch on 
all fours. The diet consists of fruits and insects. 

The lowest members of the Primates are the lemurs, 
which show some marked pecuharities of distribution, 
as well as of structure. They are entirely absent from 
the New World, and in the Old World have apparently 
been pushed far to the south by the development of 
better organized forms, or by the attacks of carnivores, 
for all lemurs are very helpless animals. Existing 
lemurs occur in the tropical forests of Africa, in the 
forests of the south-eastern region of Asia, an area 
which contains many strange and primitive animals, 
and finally in the island of Madagascar. In Africa and 
Asia they are few in number, apparently in individuals 
as well as in species, and are always small in size. In 
Madagascar there are more than thirty species, and the 
individuals are abundant in every wood. Here also 
the animals reach a relatively large size, the largest 
being about two feet in length, and, as the number of 
species suggests, they show adaptations to varying con- 
ditions of life. The number of species and differentia- 



102 THE FAUNA OF 

tion of structure seem to be associated with the fact 
that the lemurs here are protected by isolation, Hving 
as they do on an island where there are no true monkeys 
nor apes, and where the carnivores of the cat family 
are absent, members of the less differentiated civet 
alhance taking their place. 

Lemurs are less intelligent than monkeys, and much 
less highh' differentiated, but they are no less definitely 
adapted to arboreal hfe. It is therefore the more 
interesting to find that, just as baboons are monkeys 
which have abandoned the arboreal hfe, so in Mada- 
gascar we find the ring-tailed lemurs, foxy-looking 
animals, which Hve among rocks in regions where trees 
are virtually absent. We have already spoken of the 
fact that the galagos of West Africa have an elongated 
ankle which, though the mechanism is a httle different, 
gives them the power of leaping Hke a frog. The same 
peculiarity occurs in the mouse-lemurs (Chirogale) of 
Madagascar, and is even better developed in the httle 
tarsier (Tarsius) of the Malay region, which progresses 
by leaping from one branch to another, or from one 
end of a branch to the other. 

We have not hitherto spoken of bats here, because 
those forms which occur in temperate regions show no 
special adaptation to any particular type of habitat. 
It is otherwise with the large fruit-bats, which are 
practically limited to the tropical regions of the Old 
World, where they are chiefly found in forests. They 
are entirely absent from the New World, but in the 
east extend southwards to the island continent of 
Austraha and to Tasmania, though not to New Zealand. 
The fruit-bats are larger than the insect-eating forms, 
the common fruit or fox-bat of India measuring four 
feet from tip to tip of the wing. Their mastery of the 




Fig. 25. Male and female of the Black Lemur, Madagascar. The 
male only is black, the female being brown with a white rufif. Note 
the opposable thumb and great toe. Though the general shape is 
monkey-lilie, the foxy faces should bo contrasted with those of 
monkeys (Figs. 23 and 24). {From a specimen in the Royal Scottish 
Museum. ) 



THE TROPICAL FOREST 103 

air is less complete than in the insect-eating forms, the 
arrangement of the tail apparently preventing them 
from giving those sharp turns so necessary in an animal 
which feeds on insects caught on the wing. Further, 
as the fruit-bats feed in trees they are more arboreal in 
habitat, being able to scramble about the trees, attach- 
ing themselves by the hind feet, and by the strongly 
hooked thumb of the hand. Similarly the index finger 
is not reduced to the rudimentary condition seen in 
other bats, where it is useless, and is here usually fur- 
nished with a claw. Fruit-bats spear their food with 
the claw of the thumb, and have teeth so modified as 
to allow them to crush pulpy fruits. From the diet 
the animals must necessarily have been once confined 
to regions where wild fruits were abundant, but, like 
some members of the order Primates, they have taken 
advantage of man's fondness for fruit to extend their 
range to regions where his plantations can be robbed. 
In Australia, where wild fruits are somewhat rare, the 
fruit-bats seem to devour the flowers of the eucalyptus, 
but the way in which they raid the orchards of the 
fruit-growers shows that fruit is greatly preferred when 
it can be obtained. 

In the forests of tropical America there occurs an 
interesting family of bats, the Phyllostomatidae, or 
vampire bats, some of whose members present a curious 
analogy to the fruit-eating bats of the Old World, The 
vampire bats belong to the insect-eating section (Micro- 
chiroptera) of bats, but nevertheless some of them eat 
fruit only. Others eat fruit and insects, while others 
again are purely blood-suckers. 

We have already pointed out that insectivores are 
peculiarly helpless animals, without the intelligence 
which enables many of the Primates to escape from 



104 THE FAUNA OF 

the consequences of their own incapacity for defence. 
The tropical forests offer great possibilities in the way 
of shelter and protection, and it is therefore not remark- 
able that various forms should show special adapta- 
tions to life here. The most striking of these adaptations 
are those shown by a very aberrant animal, the so- 
called flying lemur (Galeopithecus), of which two 
species occur, one in the Malay Peninsula, Borneo, 
Sumatra, and adjacent regions, and the other in the 
PhiUppine Islands. The flying lemur is about the size 
of a cat, and resembles the flying squirrels of temperate 
forests in having a parachute of skin extending from 
the fore to the hind limbs, which enables it to take 
flying leaps from tree to tree. The membrane is, how- 
ever, better developed, in that it involves the tail as 
well as the limbs. The fingers and toes are short and 
strongly clawed, and they, together with the sHghtly 
prehensile tail, enable the animal to swarm up trees, 
for it cannot fly in the sense of ascending against 
gravity. It feeds upon leaves, and has strongly cusped 
front teeth, presumably for the purpose of nibbling the 
leaves. The animal altogether offers a curious example 
of adaptation to forest life. 

In the same region as the flying lemur, but extend- 
ing also into the mainland of India and Burma, we find 
the little tree-shrews (Tupaia), which so far as adapta- 
tions go may be said to be comparable to ordinary 
squirrels, as Galeopithecus is to flying squirrels. The 
tree-shrews are very like squirrels in appearance, 
though smaller than most. The feet are naked beneath, 
with sharp claws to allow the animals to cling to the 
rough bark, the tail is long and bushy, and the animals 
use their forefeet like squirrels in feeding, sitting up 
on their hind-legs and holding the insects or fruits in 



THE TROPICAL FOREST 105 

the forepaws. Structurally, of course, the tree-shrews 
are very different from the squirrels, so that the resem- 
blances are due to adaptation. Their much more 
limited distribution shows that they have been much 
less successful than squirrels. 

The powerful and intelligent carnivores have many 
representatives in the tropical forests, though their 
dominance makes it less necessary for them to acquire 
purely arboreal habits than for more helpless animals. 
They haunt the forest for food rather than for protec- 
tion. Of the large forms the lion is not a forest animal, 
though occasionally found in forest regions. The tiger, 
in India especially, is much more frequently found in 
wooded regions than elsewhere, but this may be partly 
because it is very impatient of great heat. It is appar- 
ently a bad climber. On the other hand, the widely 
distributed leopard climbs well, being capable of run- 
ning up a straight-stemmed tree. This is even more 
true of the South American jaguar, which in swampy 
regions may be almost purely arboreal in habitat, and 
preys largely upon monkeys. It shows, however, like 
the other large cats, considerable adaptability^ being 
found in savanas as well as in forests. 

The puma (Fig. 26) does not appear to haunt dense 
forests, being much more a denizen of open plains or dis- 
tricts with thick reeds and grass. The clouded leopard 
or tiger (Fig. 45) is an arboreal form found in South- 
East Asia. The smaller cats, with the exception of 
Madagascar and Australia, are universally distributed, 
and the tropical forests of aU regions have their full 
share of species. 

On the other hand, the less differentiated forms known 
as civets (family Viverridae) are limited to the warmer 
parts of the Old World. The habits of the civets are 



106 THE FAUNA OF 

varied, but among the arboreal forms we may note the 
palm-civets or tree-cats (Paradoxurus) of India and 
West Africa, which have naked feet, a common feature 
in arboreal animals, and the bear-cat (Arctictis) of 
South-East Asia, with a prehensile tail. 

Though not a few of the dog alliance extend into 
wooded country, none can be said to have any special 
adaptation to forest life. 

On the other hand, the bears and their allies, despite 
their total absence from Africa south of the Sahara, 
and their general preference for temperate and upland" 
regions, are well represented in the tropics. Thus the 
forests of South-East Asia contain the small black 
Malayan bear {Ursus malayanus), which is essentially 
arboreal and frugivorous in habit. In the forests of 
India the sloth-bear {Melursus ursinus) is common, and 
lives in forest regions, though it is a clumsy climber. 
Of the raccoons, the coatis (Nasua) are found in the 
forests of South and Central America, and the kinkajou 
{Cercoleptes caudivolvulus) of the tropical forests of 
America, a cat-like animal, has as special arboreal 
characters a prehensile tail, naked feet, and strong 
claws. It feeds upon small mammals, birds and their 
eggs, and fruits. The widely distributed weasel family 
has representatives in the tropical forests, but the animals 
do not predominate here as they do in the north, and 
the tropical forms show no special features of interest. 

As a general rule ungulates are not abundant in the 
tropical forests, their bulky bodies not fitting them for 
life amid dense and tangled undergrowth. The deer of 
temperate woods are, however, represented in the 
tropical jungles, though perhaps the majority of the 
tropical Asiatic deer tend to haunt relatively open 
country. In Africa, where deer are absent, some of the 



THE TROPICAL FOREST 107 

antelopes have become modified for forest life. This is 
especially true of the little duikerboks (Cephalophus), 
whose slender bodies enable them to glide through the 
undergrowth. The African harnessed antelopes (Trage- 
laphus) also, and the African sable antelopes (Hippo- 
tragus) are found in wooded country. In the African 
tropical forest also is found the rare and little-known 
okapi, a relative of the giraffe, but with stripes recall- 
ing those of a zebra (Fig. 46). 

In tropical Asia the sambar and its allies are the chief 
deer of forests, but the muntjacs (Cervulus) also haunt 
wooded country, choosing upland regions. In the 
dense jungles of South-East Asia occur various members 
of the genus Tragulus, including small, almost rodent- 
like animals, of primitive structure, called chevrotains. 
They are the smallest of living ungulates, being only 
about a foot in height, and their slender legs and bodies 
enable them to glide through the jungle, and thus to 
persist despite their generalized structure. An allied 
form, the water chevrotain, occurs on the west coast 
of Africa, where it inhabits swampy regions. 

In a densely forested region, rivers or swamps, with 
their special types of vegetation, obviously afford 
advantages to animals not fitted for arboreal life 
proper. We find, therefore, that such parts of the forest 
have special animals. The wild pigs of India and the 
adjacent regions, the bush pigs of Africa, are examples 
of forms which haunt the damper parts of forests. 
Africa has also its hideous wart-hogs (Phacochoerus) 
while the islands of Celebes and Buru lodge in their 
forest the curious babirusa with its enormously elon- 
gated tusks. America has no true pigs, but the slender- 
limbed peccaries replace them, and are similarly 
inhabitants of the swampy parts of forests. All these 



108 THE FAUNA OF 

pig-like animals differ from those ungulates which live 
on hard ground in the greater number of functional 
toes, in the way in which these toes spread out to pre- 
vent the animal sinking in the mud, and in the absence 
of the elaborate arrangement which enables a sheep 
or an antelope to swallow large quantities of partially 
masticated vegetable food, which is regurgitated and 
thoroughly masticated later, when the animals feel 
themselves relatively safe from pursuit. 

Among the odd-toed ungulates the tapirs, both the 
Malayan form and those occurring in South America, 
are forest animals, haunting much the same regions as 
do the pigs. The great enemy of the American forms is 
the jaguar, and the fact that when attacked the animals 
endeavour to reach thick cover suggests that the forest 
habitat is partially determined by the need for protec- 
tion. As in the case of the pigs it is probably partially 
determined also by the need for finding relatively soft 
and succulent food, for the teeth of pigs and tapirs 
have not the elaboration of structure found in the more 
highly differentiated ungulates. 

The rhinoceroses show somewhat different conditions 
in regard to habitat, for while some haunt more or less 
open plains, others, like the Javan and Sumatran 
rhinoceroses of South-East Asia and the common 
rhinoceros of Africa, are found in forested country, and 
subsist largely on leaves and twigs. Horses are not 
forest animals. The elephants, on the other hand, both 
Indian and African, are found in dense jungles, but in 
both cases this seems to be largely on account of the 
animals' great intolerance of heat, for they emerge 
into the more open regions both at night and during 
the cooler parts of the day. 

Among the rodents, the squirrelsrand flying squirrels. 



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Fig. 27. The African Elephant. 
{From a specimen in the Royal Scottish Museum.) 



THE TROPICAL FOREST 



109 



already described in temperate forests, are also found 
in tropical ones, the squirrels reaching their maximum 
number in the Malayan region. India and the adjacent 
regions have large flying squirrels belonging to the 




Fio. 28. Elephant in teak forest, Upper Burma. The position 
brings out the peculiarities of the hind-limbs, which are very different 
from those of cow or horse. Note especially that the long, straight 
thigh is not bound down by skin as in the horse, and the true knee 
appears to be very low down. {Photo by Gol. Couchman.) 



genus Pteromys, but Africa has forms which belong to 
quite a different family (Anomaluridae). The Latin 
name is given on account of the peculiar tail, which 
has overlapping horny scales on its under surface near 
the base, stated to be used in obtaining a hold on the 
bark when the animals are climbing trees, and thus 



no THE FAUNA OF 

offering some analogy to the stiff tail of the wood- 
pecker (p. 47), which has the same function. 

We have already spoken of the Canadian porcupine 
(p. 43) in the taiga. This is represented in the 
tropical forests of Mexico and Brazil by the tree- 
porcupines of the genus Syntheres, which present 
some interesting adaptations to arboreal life. The tail 
is markedly prehensile, and the hind-foot is so inserted 
as to make it easy for the animals to grasp the branches. 
The great toe is absent, but its place is taken function- 
ally by a fleshy lobe which can be bent inwards so 
as to be partially opposed to the toes. The animals 
are stated not to drink, and probably do not descend 
voluntarily from the trees (see Fig. 30). 

We have already repeatedly emphasized the fact 
that ungulates in America are few, and that their place 
in nature is taken there by rodents ; there is, therefore, 
nothing surprising in finding that the rodents called 
agutis (Dasyprocta) haunt the forests of Brazil and 
elsewhere, and have become adapted for life in the 
dense jungle. With their slender limbs and bodies 
they show a close, though entirely superficial, resem- 
blance to the chevrotains of South-East Asia. The paca 
(Coelogenys) has similar habits. 

With the Edentates we come to a primitive order, 
whose members have kept their hold in a world which 
has grown, beyond them either by retiring to the depths 
of the tropical forests, or by acquiring burrowing and 
concealed habits. In the forests of the Amazon occur 
the sloths, belonging to the genus Bradypus and 
Choloepus, perhaps the most truly arboreal of all 
mammals, for they are quite helpless if removed from 
the trees among which they pass their whole lives. 
The fact thai^they possess practically no adaptation 





Fig. 29. An African Flying Squirrel {Anomalurus). |The characteristic 
scales on the under-surface of the tail cannot be seen in this specimen, 
but the bony structure projecting from the elbow, which helps to support 
the parachute, is well shown. With this figure should be compared 
that of the Flying Phalanger (Fig. 33). Though not nearly related the 
animals show a superficial resemblance to one another. {From a specimen 
in the Royal Scottish Museum). 





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THE TROPICAL FOREST 111 

to permit them to pass from one tree to another shows 
that their natural habitat is the dense forests where 
tree is bound to tree by lianes. 

Among the special features we may note the nature 
of the coat, the individual hairs having a fluted surface, 
on which algae lodge, and so give the animals the 
appearance of a lichen-covered branch. The fingers 
are converted into mere hooks, the tail is a stump, 
a common feature in such arboreal animals as have 
not prehensile tails, or do not require to use the tail 
as a balancing organ after the fashion of squirrels and 
tree-shrews (cf. bears, anthropoid apes, &c.). We have 
already spoken of the elongation of the forelimbs in the 
sloths (p. 95). The food consists of leaves and fruits and 
the animals do not drink. The usual position is hang- 
ing back downwards from the branches of trees, and the 
animals sleep rolled up in a ball with the head tucked 
between the arms. Like many helpless forms they are 
active only at night (see Fig. 32). 

The South American ant-eaters are also forest animals, 
the large form called Myrmecophaga jubata being strictly 
terrestrial, while the little two-toed ant-eater (Cyclo- 
turus didactylus) is arboreal, and except that it has 
a prehensile tail and lives upon insects, has a curious 
adaptive resemblance to a sloth, both in the struc- 
ture of its limbs and in appearance. The hairy ant- 
eaters of South America are replaced in India and 
Africa by the scaly ant-eaters or pangoHns (Manis), but 
though some of these are partially arboreal, most are 
found in rocky country, where they burrow in the 
ground. 

Not a few of the marsupials have acquired arboreal 
habits. Thus the tropical forests of New Guinea and 
Queensland are inhabited by tree kangaroos, which have 



112 THE FAUNA OF 

apparently recently taken to the trees, for they are 
stated to be slow and clumsy climbers. In other 
kangaroos the forelimbs are very short, in these forms 
they are nearly as long as the hind ones, and the tail, 
though not prehensile, is said to be used in climbing. 

Much more definitely arboreal are the phalangers, 
closely related animals, but as well fitted for life in the 
trees as most kangaroos are for life on the ground. In 
the forests of Western Australia occurs the little Tar- 
sipes, a shrew-like animal with a prehensile tail, which 
sucks honey from flowers with its worm-like tongue, 
and presumably, like humming birds, obtains insects 
also in this way. In North Australia and in the islands 
of the Indo-Malayan region is found the spotted cuscus 
{Phalanger maculatus). As in the other members of 
the phalanger family the great toe can be opposed to 
the others, and the long tail is very markedly pre- 
hensile. Cuscuses feed upon leaves and fruit, but like 
so many of the forest animals will also take birds and 
other small creatures. There are several species, mostly 
about the size of a cat. The feet are naked beneath. 

Just as we have flying squirrels among the rodents 
and flying shrews among insectivores, so among the 
phalangers (Fig. 33) we have also flying types. The 
great flying phalanger {Petauroides volans) of Queens- 
land and Victoria has both a flying membrane and 
a prehensile tail ; the squirrel flying phalanger or sugar- 
squirrel {Petaurus sciureus) has a bushy squirrel-like 
tail, not prehensile, and a well-developed parachute. 
It occurs in Eastern Austraha. The pygmy flying 
phalanger {Acrobates pygmaea), in which the total length 
of head and body does not exceed about 2^- inches, 
has a long tail with the hairs arranged at the sides to 
imitate the vane of a featner, and a slightly developed 




fe 




Fig. 33. The Lesser ilyiug Piialaiiger of Eastern 
Australia. (From a specimen in the Royal Scottish 
Museum.) 



THE TROPICAL FOREST 113 

parachute. It is stated to show marvellous agility in 
leaping from branch to branch, and is doubtless aided 
by its feather-like tail. 

Another member of the phalanger family, the koala 
or native bear {Phascolarctos cinereus) is very different 
from its allies in appearance, and shows some curious 
adaptations. It is sluggish in its movements, and, as 
often happens in such cases, the tail has disappeared 
(cf. bear, sloth, &c.). In the hand two of the fingers 
can be opposed to the other three, the condition which 
occurs in the chameleon. On the foot, as in other 
phalangers, there are five toes, the great toe being 
opposable to the others. The animal feeds chiefly 
upon leaves, but is also stated to descend to the ground 
in order to dig for roots. Curiously enough, it possesses 
cheek pouches like an Old World monkey. 

The last of the marsupials to be considered are the 
opossums of South America, small insect-eating animals 
with opposable great toes and prehensile tails, which, 
though chiefly South American, are represented in the 
United States by the widely distributed common 
opossum {Didelphys marsupialis). They must be added 
to the very considerable list of peculiar arboreal mam- 
mals possessed by South America, for they do not occur 
outside of the American continent. The majority 
spend their lives in trees, though some spread to the 
pampas of Argentine, and they take the place in nature 
elsewhere occupied by insectivores, which are absent 
from the South American continent (see Fig. 31). 

Birds are so abundant in the tropical forests that we 
can only pick out for special remark a few which illus- 
trate points of interest. In spite of the gloom of the 
jungle brilliantly coloured forms are common, a fact 
well illustrated by the gorgeous birds of paradise, the 

1404 H 



114 THE FAUNA OF 

most brightly coloured of animals, which haunt the 
forests of New Guinea and the neighbouring regions. 
They spend much of their time in the trees, to whose 
branches they cling easily with their strong feet. 

Among Picarian birds a whole division possesses the 
climbing foot, that is one in which the first and fourth 
toes are directed backwards, while the second and third 
point forwards, and almost all these are arboreal birds. 
They include the widely distributed woodpeckers, found 
in tropical no less than in temperate forests, the jaca- 
mars, handsome birds found in the South American 
forests, and the toucans with enormously developed bills 
and bright colouring. The purely frugivorous plantain- 
eaters of Africa differ in that the fourth toe can be 
turned backwards or forwards at will, though the birds 
seem to dwell entirely in the trees. The climbing foot 
is however best developed in the parrots, which are for 
the most part thoroughly arboreal. The legs are short, 
and the short, strong, hooked bill, of which the upper 
portion is hinged as well as the lower, is used in cHmb- 
ing as well as in cracking hard shells and kernels. 
Parrots are chiefly tropical, but they extend much 
further to the south of the tropic of Capricorn 
than to the north of that of Cancer. As is well 
known, their colouring is often very striking, green 
predominating, as it often does among arboreal, fruit- 
eating birds. 

Of the parrots, the crested cockatoos are Australian, 
and the gorgeously coloured macaws with their long 
tails South American. The little love-birds are African, 
as is also the familiar grey parrot with a red tail. The 
parakeets are found in Africa, India, and Australia. 
Of almost all parrots it may be said, as of the fruit- 
eating mammals, that they show a marked preference 



THE TROPICAL FOREST 115 

for robbing man when they can, rather than hmiting 
themselves to wild products. 

Not a few of the pigeons are arboreal. We may 
mention especially the fruit-pigeons, found in South- 
East Asia, and extending southwards to Australia. 
The bill is distensible at the base to permit the birds 
to swallow large fruits whole. 

Among the mammals we found that in addition to 
the truly arboreal forms there were a number like the 
chevrotains and agufis, which took advantage of the 
shelter afforded by the dense forest, through which 
their slender bodies permitted them to force their way. 
Quite similar conditions occur among the game birds, 
where various members of the pheasant family live 
in dense thickets, through which their wedge-shaped 
bodies enable them to travel easily. Such birds fly with 
considerable reluctance, preferring to trust to the thick 
cover unless danger approaches too closely. Among 
such forms we may mention the wood-partridges of the 
Malay region, the spur-fowl of India and Ceylon, the 
jungle-fowl, the guinea-fowl of West Africa, and so 
forth. 

Very remarkable is the condition presented by the 
hoatzin (Opisthocomus) of South America, where the 
young are hatched with claws on both the thumb and 
index finger, which they use in climbing about trees, 
after the fashion of a fruit-bat. The hoatzin is believed 
by some ornithologists to be related to the game-birds, 
but is a very primitive form. 

Among reptiles the crocodiles and their alHes haunt 
the lakes and rivers of forest regions, where they lie in 
wait for the forest animals as they come down to drink. 
A very curious arrangement of the breathing organs 
enables them to drown their prey by holding the 

H 2 



116 THE FAUNA OF 

animals caught under water till death takes place, 
the crocodile being meantime protected from choking 
by the nature of the internal nostrils. 

Of the lizards the flying forms (Draco) are interest- 
ing. They occur in the Indo-Malayan countries, and 
their parachute is a lateral fold of skin supported upon 
the posterior ribs, which are greatly elongated. The 
mechanism is thus entirely different from that seen in 
any fljdng mammal. The body is greatly depressed, 
and the ' wings ' when not in use are folded close to 
the body. 

The iguanas of tropical America and the West Indies 
are also arboreal forms, but show no special adapta- 
tions to this mode of life. They haunt especially trees 
overhanging water, and are said to have the curious 
habit of dropping into the water with a splash, some- 
times from a great height, if alarmed. The most purely 
arboreal of the lizards are, however, the chameleons, 
specially characteristic of Africa, but also found in 
India and Ceylon, and extending into Europe in Spain. 
All have prehensile tails, and the hands and feet con- 
stitute perfect grasping organs. The limbs are long 
and slender, the forelegs especially so. The fingers and 
toes form two groups, two being opposed to the other 
three. On the fore-limb the first three fingers form an 
inner bundle opposed to the fourth and fifth, which 
are outside. In the foot the inner bundle is made up 
by the first two toes only, the third, fourth, and fifth 
forming the outer group. The animals are insecti- 
vorous, and their power of colour-change is famiHar 
to all. 

Of the snakes the tree boas of South America are 
forest-haunting forms, with prehensile tails, and feed 
chiefly upon birds. Like their allies the pythons and 



THE TROPICAL FOREST 117 

true boas, they are non-poisonous, crushing their prey 
by the weight of their coils. The huge anaconda 
{Euneces murinus) of the Amazonian forests is semi- 
aquatic, lurking in pools till its prey approaches the 
water. It feeds largely on peccaries. The true boas 
occur both in Madagascar and in tropical South America, 
and inhabit the dense forests, through which they can 
glide without difficulty. The beautifully coloured and 
marked wood-snakes (Herpetodryas)of tropical America 
represent there the tree snakes (Dendrophis) of the Old 
World, all of which are arboreal in habit. The American 
forms feed upon lizards and young birds. In India the 
very agile whip-snakes (Dryophis) twine their slender 
bodies round branches of trees, shooting out their heads 
in order to capture their prey. Most other snakes, includ- 
ing the most poisonous forms, are ground animals, 
often inhabiting dry and sandy places. An exception 
is the climbing tree-viper {Trimeresurus gramineus) of 
India and Burma, with a markedly prehensile tail, and 
a generally green tint, like the trees among which 
it lives. 

Of the amphibians we have already mentioned the 
flying frogs of the genus Rhacophorus, which occur in 
Madagascar, and also throughout South-East Asia. 
A number of other frogs show more or less well-marked 
arboreal habits, the commonest adaptation being the 
development of some form of adhesive disks at the end 
of the toes, to permit of the animals fixing themselves 
to the branches of trees. This is seen in the family of 
Dendrobatinae, whose members occur alike in Mada- 
gascar and in tropical America. They are beautifully 
and often vividly coloured, and some species at least 
have poison glands in the skin, whose secretion is used 
in South America as an arrow poison. Such an associa- 



118 THE FAUNA OF 

tion of bright colouring with poisonous or noxious 
quahties is of common occurrence in animals. 

The typical tree frogs of the family Hylidae are 
widely distributed over the globe, but are absent from 
Africa south of the Sahara, from Arabia, and from 
India. They have suctorial disks at the ends of their 
toes, are usually protectively coloured in shades of 
green, the tints varying with the surroundings, and 
have glands upon the under surface whereby they can 
absorb water from the damp leaves on which they rest, 
and thus obviate the necessity for seeking ponds to 
moisten the skin. Their breeding habits are often 
peculiar. Other amphibians are not adapted for the 
arboreal Hfe. 

In regard to fresh- water fish we may note one or two 
peculiar forms, found in the streams of the tropical 
forest, or on its seaward margin. The very peculiar 
double-breathing fishes, which are animals furnished 
both with lungs and gills, are represented in the tropical 
streams of Queensland by Ceratodus, in the tropical 
streams of Africa by Protopterus, and in those of 
South America by Lepidosiren. None of these animals 
voluntarily quit the water, but the fact that the two 
last named can breathe when buried in the mud as well 
as when swimming in water adapts them for life in 
tropical regions, where there is often a well-marked 
alternation of wet and dry seasons. 

Even more curious are the habits of the mudskippers 
(Periophthalmus), which haunt the mangrove swamps 
and mud-flats on the shores of the Indian and Pacific 
Oceans and off the coast of West Africa. These are 
bony fish which are partially adapted for Hfe on land. 
The anterior fins are curiously modified, so that the fish 
can cUmb about the supporting roots of the mangroves, 



THE TROPICAL FOREST 119 

and it can also leap and skip over the mud. The eyes 
are very prominent, are furnished with distinct eyelids, 
and are protrusible. The fish, which are very tadpole- 
like in appearance, feed upon insects. 

In India and the south-east of Asia generally, another 
fish is found which can live on land, and voluntarily 
leaves the water to do so. This is the climbing perch 
{Anabas scandens), a freshwater form which travels 
long distances over land by hitching its pectoral fins 
round plants. The fish is also stated to be able to 
climb trees. It has a special accessory breathing organ, 
which enables it to breathe air when out of the water. 

In regard to the invertebrates, a special feature of 
the tropical forests is the great wealth of insects. That 
this must be so will be clear when we reflect that 
some of the forest-dwelling primates, the insectivores, 
many of the marsupials, some carnivores, the eden- 
tates, many reptiles and amphibians and so on, eat 
insects, either solely or in combination with other types 
of food. Further, the equal temperature allows the 
insects to go on breeding all the year round, and thus 
permits a great wealth of individuals to occur, while 
the special conditions favour a great wealth of genera 
and species. Apart from the size and beauty of the 
tropical butterflies, the most impressive of the insects 
are first the flies, which are often blood-suckers, and 
then may, as in the case of mosquitoes and tsetse flies, 
serve as transmittors of the tropical diseases most fatal 
to man and beast, and second the ants, some of which 
are extraordinarily destructive to plant life, while 
others from their numbers and ferocity are the enemies 
of all other animals. The driver ants of West Africa, 
which are wandering forms, are stated to devour every 
living creature in their path which cannot make its 



120 FAUNA OF THE TROPICAL FOREST 

escape, and will even attack human beings if from any 
cause these are rendered incapable of defence or flight. 

The termites, or so-called white ants, are as a rule 
less obvious in the dense forest than in more open 
country, but some species do occur there. Other 
members of the same order form the beautiful stick 
and leaf insects, predatory forms which often show 
a marked resemblance to the vegetation among which 
they live. As well as with insects the tropical forest 
swarms with scorpions, spiders, including the large 
bird-catching form of South America, and ticks, which, 
like flies, serve for the transmission of deadly diseases. 
As most of these forms do not, however, show special 
adaptations to forest life, it is sufficient to merely 
indicate their abundance, which has a marked effect 
upon the life of other organisms in forest areas. 

We may add that, just as a few fish in tropical 
climates have taken advantage of the greater oppor- 
tunities which the land offers as compared with the 
sea to acquire partially terrestrial habits, so various 
crabs have become partially adapted for life on land, 
and wander about in those forest regions which are at 
no very great distance from the sea. to which they 
return for breeding purposes. 

References. In regard to the animals of the African forests, Sir 
H. H. Johnson's works give very full details, with many figures ; see 
British Central Africa (London, 1897) ; The Uganda Protectorate (2 vols., 
London, 1902) ; Liberia (2 vols., London, 1906). Lydeker's Game 
Anitnals of Africa (London, 1908) should also be consulted. Wallace's 
Malay Archipelago (London, 1869) gives a fascinating account of the 
animals of that region, and the same author's Tropical Nature (London, 
1878) may also be mentioned. Bates's Naturalist on the Amazons (5th ed., 
London, 1884), and Belt's Naturalist in Nicaragua (2nd ed., London, 
1888), give good accounts of South and Central American animals. For 
details as to the animals, reference should again be made to the natural 
histories already mentioned. 



CHAPTER VI 

TROPICAL SAVANAS AND DESERTS 

In the tropics the steppes of temperate latitudes are 
represented by what are called savanas, which are 
regions where grass occurs, mingled with arborescent 
or shrubby vegetation. Sometimes we have in these 
regions scattered trees only ; sometimes clumps of 
trees occur, separated by regions without trees, giving 
a characteristic park-like appearance to the landscape. 
Elsewhere the trees follow the courses of the streams, 
forming the so-called gallery forests. Such savanas 
occupy large stretches in the tropical regions of Africa, 
South America, and Australia, and have a highly 
developed and characteristic fauna. 

The typical savana climate is tropical. The rain 
comes in the hotter season of the year, and there is 
a well-marked dry season. Where the rain is deficient 
the savana passes into desert, as we see in passing 
northwards from the Sudan to the Sahara, or inland 
from the Australian bush to the central desert. On the 
other hand, where the rainfall is abundant the trees 
increase in number, and the savana passes into the 
tropical rain-forest, through the intervention of the 
savana wood, with its numerous trees. The period of 
greatest vegetative activity accompanies or follows the 
rainy season, and the dry season may witness an almost 
complete cessation of activity. This, like the similar 
conditions in the steppes, involves a certain amount of 
migration among the inhabitants of the region. Further, 



122 



TROPICAL SAVANAS 



owing to the great power of the sun, bush fires are 
frequent, and often have devastating effects. 

The type of vegetation naturally varies in the 
different regions in which savanas occur. In Africa 
the mighty baobab [Adansonia digitata) is conspicuous 
among the trees. It stores water in its thick trunk, 



j#. 







i 




v"'-^ 


if 


.wm^mf^ 


i| 




Mim::^S^:^i^^m>^^^^a^:p^^mA 




' ■i'-'T~."''~^'^s»ji;''^#'lk'~^s>««' , 



Fig. 34. 



Savana, with scattered acacias, on the margin of the desert 
in Kordofan. {Photo by Capt. Lloyd.) 



and becomes leafless in the dry season. Other important 
trees are thorny acacias, whose foliage is reHshed by the 
giraffe, various species of cactus-like Euphorbia, palms, 
and so forth. Various kinds of grasses occur, and often 
grow to a great height, forming dense thickets, which 
offer much shelter, while thorny and xerophilous plants 
are of course frequent. In the savanas of the other 



AND DESERTS 123 

continents, though the species differ, the general facies 
is the same-^tall grasses, thorny acacias, cactuses or 
cactus-hke forms, and generally plants presenting 
special features which protect them against periodical 
drought, while allowing them to take advantage of the 
periodic tropical downfalls. 

Of the great savana regions of the world the African 
is especially rich in ungulates, notably in antelopes, 
the Australian in herbivorous marsupials, notably 
kangaroos and wallabies, while the savanas of South 
America, a country which has witnessed an extra- 
ordinary destruction of mammalian types in recent 
geological time, were relatively poor in mammalia till 
the advent of European man. 

One of the special climatic features of the savana 
proper is the periodic abundance of rain. As we pass 
from the savana to the desert the dry season increases 
in length, and the rain becomes less, and more un- 
certain. Vegetation also gradually diminishes as the 
conditions become less favourable, and the fauna 
becomes impoverished, the mammahan fauna diminish- 
ing first. In the desert proper few organisms can live, 
but the less unfavourable regions carry a reduced 
savana fauna, especially of insects and reptiles. The 
Kalahari, indeed, is said to serve as a reservoir for such 
insects as locusts, which breed there until starvation 
forces the swarms to sweep outwards to the better 
watered lands on the margin of the desert. 

No hard and fast line separates savana regions from 
steppes, this being especially true in South America, 
where the treeless ' pampas ' or steppes of the Argentine 
south of lat. 32° S. pass into a savana region further 
north. It should be noted, however, that in addition 
to the characters already given, typical savana regions 



124 TROPICAL SAVANAS 

are distinguished from the typical steppe region already 
described in the absence of a severe winter. 

Proceeding now to consider the animals of the various 
savana regions in systematic order, we may note that 
as a general rule the primates do not occur in such 
regions, being, as we have seen, mostly fitted by nature 
for hfe in the tropical forest. To this rule, however, 
the baboons form an exception, for, as we have already 
seen, they are quadrupeds, hving in open rocky country. 
The Arabian baboon {Papio hamadryas) occurs abun- 
dantly in the Sudan, where it feeds upon fruits, shoots, 
buds, and seeds, and finds the necessary shelter in 
rocky ground. In Angola another species (P. anuhis) 
inhabits very dry country, and feeds largely upon that 
strange coniferous plant known as Welwitschia. 

Among the insectivores we may note especially the 
jumping shrews, which are confined to Africa, and 
show a curiously close resemblance to the jerboas among 
rodents. The jumping or elephant shrews have greatly 
elongated hind-legs, and move in a series of leaps. They 
have also curiously elongated snouts, which they use 
in routing about for the insects on which they feed. 
The type genus is Macroscelides, and the animals are 
widely distributed in Africa, being mainly but not 
exclusively tropical. The elongation of the hind-limbs 
is interesting, for it is frequent in steppe and savana 
animals, and has several obvious advantages which have 
been already discussed (see p. 64). 

Of the carnivores, the large cat-hke forms, as we 
have already had occasion to remark, show no very 
special adaptation to one habitat. The uniform colour- 
ing of the lion, however, suggests that it was once 
a desert animal. In Africa it is abundant in the Kala- 
hari desert, but also extends into savana and steppe 



AND DESERTS 125 

regions, its distribution being probably determined by 
the double need of avoiding the proximity of its per- 
sistent enemy, man, and of following its natural prey, 
the larger ungulates. Of the smaller cat-like forms, the 
mongooses are ground animals, usually haunting open 
country, and avoiding dense forests. An allied form, 
the meerkat (Suricata tetradactyla) haunts sandy ground 
in Cape Colony, where the savanas pass into steppes. 
Like most of the smaller mammalia of open country 
this animal is a burrower, making deep holes in 
the sandy veldt with its sharp foreclaws. Another 
adaptation to life in this region is shown by the fact 
that it feeds chiefly upon the bulbs and roots of 
the veldt plants, which store water in their under- 
ground parts during the time of drought. Another 
steppe or savana form of wider distribution is the 
aard-wolf {Proteles cristatus), a burrowing animal, with 
weak teeth, which seems to feed largely upon termites, 
and inhabits open country throughout the southern 
half of Africa, with a northern limit apparently in 
Somaliland, where it has been once found. The hyaenas 
are also inhabitants of savana country, the spotted 
hyaena of Africa being often found in the same districts 
as the lion, upon which it is partly dependent, in that 
it obtains the remainder of the ' kill ', when the nobler 
animal has satisfied its hunger. 

As a rule the members of the dog alliance inhabit 
open country, as the common habit of hunting in packs 
suggests. A considerable number occur in the tropics, 
and may therefore be included in the fauna of deserts 
and savanas. We may note especially the African 
jackals, which hunt in packs and feed upon rodents, or 
the smaller ungulates, or sick or wounded members of 
the larger species. An interesting desert species is the 



126 TROPICAL SAVANAS 

long-eared fox, or fennec, which inhabits the Sahara 
desert, and is called Canis zerda. This little animal 
has very large ears and great acuteness of hearing ; it 
is tawny-coloured like the desert sand, and is burrowing 
and nocturnal in habits. It burrows with great rapidity, 
being said to appear to sink through the sand. At dusk 
it becomes active, and sets forth in search of insects, 
lizards, small birds, rodents, or even fruit if obtainable. 
The animal is partially social, the burrows being made 
in company. A very much fiercer animal is the Cape 
hunting dog [Lycaon pictus), which has a curious and 
unexplained resemblance to the spotted hyaena. It 
is widely spread throughout Africa, where it inhabits 
open country, preying upon the ungulates, which are 
borne down by sheer weight of numbers. In South 
Africa the flocks of the white man form a favourite 
source of food. Though the animals hve in holes, the 
young being born underground, yet on an alarm it 
seeks safety in flight rather than in the burrow like the 
fennec. It would appear that the dogs have little 
or no burrowing power themselves, their holes being 
either natural or obtained by ejecting the original 
occupant. So swift are these dogs that they are said 
to be able to overtake the swiftest antelope. Not a few 
other dog-like animals haunt the African savanas, but 
these may serve as types. 

Bears, as we have already seen, are absent from 
Africa south of the Atlas, and one species only occurs 
in South America, and that in the Andes. As these 
two countries have the best-developed savanas, it is 
clear that the animals are unfitted for life in such 
regions. They are indeed absent aUke from temperate 
steppe and tropical savana and desert. The allies of 
the bears, such as the raccoons and coatis, are also 



AND DESERTS 127 

absent from savanas, and the weasel group is not well 
represented there. Among the few weasel-like forms 
we may note the South African weasel (Poecilogale) and 
the Cape polecat (Ictonyx). The latter has a somewhat 
wide distribution in Africa, and differs from martens 
and polecats in that it is unable to climb. It has 
a peculiar resemblance to the American skunks, and 
like them is protected from possible enemies by its very 
offensive odour. The animals feed upon small mammals 
and birds, lizards, and frogs, and are found in rocky 
districts. 

It is when we come to the ungulates, however, that 
we find the most specialized and abundant of the 
animals of the African savana. In the reedy swamps 
throughout the greater part of the continent occurs the 
so-called Cape buffalo {Bos coffer), which is replaced in 
the regions richer in trees by the short-horned buffalo 
{Bos pumilus). Both live in herds, and do not volun- 
tarily quit the vicinity of water, in which they love to 
bathe. The young are born in the warmer season, and 
there is never more than one calf at a birth. It is 
hidden by the mother among long grass, and for about 
ten days after its birth the mother separates from the 
herd, and remains within easy reach of her young, 
which she visits at short intervals. This habit speaks to 
hfe in regions where cover is always obtainable, and is in 
striking distinction to the habits of the mountain ungu- 
lates (cf. p. 75), where the young must be able to 
travel with the herd very shortly after birth. 

As we have repeatedly stated, it is the antelopes 
which characterize specially the savanas of Africa, 
the diversity of species being as remarkable as the 
number of individuals, till man interfered. In several 
points of structure antelopes are more primitive than 



128 TROPICAL SAVANAS 

oxen or sheep and goats, and they appear to be 
older. 

Eland are the largest African antelopes, and are 
distinguished by the presence of horns in both sexes. 
They were formerly common over the whole of 
Eastern and Southern Africa. Typical savana animals, 
they prefer open plains with scattered timber, 
but extend into the desert on the one hand and into 
the open savana wood on the other. Like not a few 
tropical animals they are intolerant of the hot sun, 
and where possible spend the hours of greatest heat in 
the shelter of woods, moving back to the grassy plains 
to feed and drink. Where possible they drink daily, 
but unlike the buffaloes they can tolerate thirst, and in 
the Kalahari desert apparently obtain sufficient water 
by eating water-melons and similar succulent fruits or 
plants. Like most ungulates they live in herds, and the 
student of botany will notice that the fodder plants 
upon which these animals depend (grasses, &c.) are 
social also, while in the tropical forests, where social 
animals are rare, social plants are also infrequent 
(cf. p. 96). 

Kudu (Strepsiceros) are distinguished from eland by 
the absence of horns in the female, as well as by other 
characters. They haunt thickets and country covered 
with bush, and occur in small parties, usually on very 
rough ground. Their speed is not very great. The 
preference for bush or thicket-covered country is even 
more marked in the harnessed antelopes (Tragelaphus), 
which we have already mentioned as being found even 
in the tropical forest. On the other hand, the addax 
from the deserts of North Africa and Arabia, and the 
gemsbok {Oryx gazella) from the deserts of South- 
western Africa, are examples of forms which inhabit 



AND DESERTS 129 

very arid country, and appear capable of going for long 
periods without tasting water. The horns are very 
powerful, and the gemsbok is stated to be able to beat 
off the lion by means of them, but not to be swift, 
perhaps because it had few enemies till man appeared 
on the scene. In addition to the gemsbok, other 
species of the genus Oryx occur in different parts of 
Africa, all being inhabitants of open country. 

The gazelle group, largely represented in the more 
arid regions of Asia, North Africa, &c., has a South 
African member in the springbok, once enormously 
numerous on the margin of the Kalahari desert. Other 
African species also occur. An allied form of interest- 
ing habits is Waller's gazelle {Lithocranius walleri) from 
East Africa, which inhabits rocky districts, where 
thorn-jungle occurs, and has a remarkably long neck, 
giving it a resemblance to a miniature giraffe. It feeds 
chiefly upon twigs and leaves, and is stated to rest its 
forefeet against the trees, in order to reach the foliage. 

Among other forms we may notice the pala antelope 
{Aepyceros melampus), found among the acacia scrub 
of Southern and South-Eastern Africa, and remarkable 
for its great swiftness, and for its power of taking long 
leaps. It prefers the proximity of water. In swampy 
regions where reeds are plentiful the reitbok and water- 
buck antelopes occur, the latter seeking the water or 
swamps when pursued. On the other hand, hilly and 
mountainous districts are inhabited by the active 
rhebok, which resembles a chamois. Of the little klip- 
springer we have already spoken (p. 84). The steinboks, 
also small animals, occur in open country or savana 
wood, but avoid hilly country. They are remarkable 
for their speed and their close resemblance in colour to 
the ground. 

1404 I 



130 TROPICAL SAVANAS 

The last group of African antelopes includes the 
large wildebeest or gnu, the hartebeests, and the bless- 
bok. The \vildebeests (Connochoetes) are ungainly 
looking animals, with some resemblance to oxen, which 
inhabit open country in South and East Africa. The 
genus Bubahs includes the somewhat stag-like harte- 
beest, the blessbok, and the bontebok. All the three 
mentioned are exclusively African, though one member 
of the genus extends into Syria, and frequent grassy 
plains, especially those which have so great an exten- 
sion in Southern Africa. 

Generally, we may say that very many of the African 
antelopes are typical savana animals, but some, hke 
the gemsbok, extend into the desert proper, a few, like 
the duikerboks, into the tropical forests, while not a few 
extend their range up the mountains, the klipspringer 
being a typical example, and some, hke the water-buck, 
frequent the swamps, and seek safety there. Those 
which inhabit open plains jSnd security in their numbers, 
the strength and powerful horns of the bucks, and their 
swiftness. Less powerful and slower forms must haunt 
country which offers some form of shelter, as e. g. rocky 
regions, thorny jungle, or swampy districts. 

The resistance which these wild forms offer to the 
diseases carried by tsetse-flies and ticks must have been 
a factor in their persistence, for these diseases form the 
greatest obstacles to the introduction of domesticated 
ungulates into the great plains of Southern Africa. 
The wild antelopes (cf. negro children and malaria) 
are apparently tolerant of the parasites of the various 
diseases, which affect them but httle. They thus serve 
as reservoirs of infection, by means of which introduced 
forms may be infected. The virtual absence of wild 
ungulates in South America when it was colonized from 




Fig. 36. The Giraffe drinking, showing the great difficulty which the animal 
has in reaching the ground, in spite of the length of the neck. {From a 
specimen in the Royal Scottish Museum.) 



AND DESERTS 131 

Europe meant the absence of such reservoirs of disease, 
and accounts for the greater ease with which domesti- 
cated ungulates were introduced there. It has been 
suggested as a reason for the disappearance of so many 
ungulates from South America — for they were once 
abundant there — that they were killed off by some 
parasitic disease. If this were so, then with the dis- 
appearance of the hosts the parasites must have died 
also, leaving the field clear for reintroductions later. 
In Africa we have to notice that the tolerance of minute 
blood parasites — a tolerance doubtless originally ac- 
quired at the price of a fearful death-rate — ^is a means 
of protection of the existing forms against the intru- 
sion of new and competing forms. The resistance to 
the trypanosomes carried by the tsetse-fly has even to 
some extent protected the antelopes from their great 
enemy man, for European hunters are constrained to 
avoid regions much infested by the tsetse on account 
of the difficulties of transport. 

Another very beautiful ungulate which frequents all 
the open parts of Africa south of the Sahara is the 
giraffe, which shows a pecuHar adaptation to life in the 
savana. The great elongation of the neck and of the 
forelimbs enables it to browse upon the leaves of 
the acacias and other trees of the scrub. Despite the 
length of the neck, however, drinking presents great 
difficulties, the animal being compelled to straddle its 
legs apart before it can reach to the ground. Grazing 
is similarly difficult, and is rarely practised. The giraffe 
inhabits arid country, notably the Kalahari desert, and, 
generally, sandy plains where the scrub on which it 
feeds occurs. It can apparently go many months 
without drinking. The animals go about in herds, and 
are capable of great speed. Only a single young one is 

I 2 



132 TROPICAL SAVANAS 

produced at a birth, and when three days old it can trot 
by the side of its mother, who protects it from the 
attacks of carnivores by kicks with her powerful legs. 
The large eyes and the long neck give the giraffe a 
very wide range of view, very necessary in an animal 
which frequents open country. 

Deer are usually absent from open plains, and are 
entirely absent, as we have seen, from Africa south of 
the Atlas. But in South America, where antelopes are 
totally absent, the deer extend their range to the plains 
and swamps. Thus the pampas of the Argentine and 
Paraguay, together with similar regions further south, 
are inhabited by the pampas deer (Cariacus campestris), 
which finds the necessary shelter among the long 
pampas grass. This deer occurs in pairs or small 
parties, and the female is particularly ingenious in pro- 
tecting her fawn. The latter makes off through the 
grass on an alarm, and then cowers down, while the 
mother takes herself off in another direction in a slow 
and hmping manner. 

We have spoken of the camels of the steppes of the 
Old World, and have seen also that their aUies, the 
llamas of the New, are intolerant of great heat, so that 
the tropical savanas, whether in Africa or in America, 
have no members of this family. 

Of the odd-toed ungulates the rhinoceroses, as already 
mentioned, extend into the plains, this being especially 
true of Burchell's rhinoceros, a grass-eating form. Of 
the striped horses of Africa Burchell's zebra and the 
quagga are (or were) both inhabitants of the open 
grass-covered plains, but both are chiefly extra-tropical, 
inhabiting the vast plains of the extreme south of 
Africa. The African wild ass is similarly an inhabitant 
of the arid regions of North Africa. While Burchell's 



AND DESERTS 133 

zebra and the quagga formerly occurred in vast herds, 
the wild ass, an inhabitant of a region where food is 
always scanty, occurs in smaller parties. Its sober tint 
harmonizes with the uniform colour of the desert, and 
the fact that the domesticated form will eat dry and 
prickly food points back to the days when its ancestors 
contented themselves with the thorny herbs of the 
desert. The stripes of the zebra and quagga apparently 
harmonize with the light and shade playing through 
the open bush country of their native haunts. It will 
be noted that the presence of the various forms of wild 
horses on the plains to the north and south of Africa, 
and their limitation chiefly to elevated regions in the 
tropics (Grevy's zebra), speaks to a relative intolerance of 
heat, a not uncommon feature in the larger ungulates. 

As to the rodents, we note that in Africa those of 
the savanas are relatively unimportant, while in South 
America, with the paucity of ungulates, there are many 
large and important rodents. 

We have already spoken of the jerboas, which extend 
from the steppes of Asia into the deserts of North 
Africa, and have noted their special adaptations. In 
the southern half of the continent the place of the 
jerboas is taken by the so-called jumping hare (Pedetes 
caffer), very common at the Cape, but extending north- 
wards into Angola and Mozambique. While related to 
the jerboas the animal resembles the common hare in size 
and colour, but it has a long hairy tail, and elongated 
hind-legs. It feeds upon all-fours, but escapes from its 
enemies by taking long bounds, stated sometimes to 
cover as much as thirty feet. The animals are bur- 
rowers and nocturnal, and frequent arid districts. 
True hares also occur in Africa, but offer no special 
features. 



134 TROPICAL SAVANAS 

Among the various mole-like forms of Africa mention 
may be made of the little sand-rats (Heterocephalus) 
of the sandy deserts of Somaliland. These httle animals 
— which are no bigger than a mouse — are nearly naked, 
perhaps as an adaptation to life in sandy soil. They 
resemble moles in having no external ears, and in their 
almost functionless eyes. 

Of the rodents of South America the majority have a 
wide distribution, ranging from the true savanas south- 
ward to the pampas of the Argentine and the plains of 
Patagonia. The viscacha {Lagostomus trichodactylus), 
according to Mr. W. H. Hudson the most typical 
inhabitant of the pampas, extends beyond their Hmits, 
though scarcely into the savanas proper. On the 
other hand the mole-hke tucotucos (Ctenomys) are 
burrowing animals, which occupy sandy regions from 
Brazil and Bolivia to the extreme south. The coypu 
(Myopotamus), an aquatic form haunting the banks of 
rivers and lakes, has an even wider distribution. Many 
species of cavy also occur, some being partial to moist 
situations, while others dwell in rocky regions. The 
largest living rodent, the capivara or capybara {Hydro- 
choerus capivara) has a very wide distribution, and is 
aquatic in its habits, frequenting the margins of lakes 
and rivers, but also feeding on the open plains. 

Of the South American Edentates most of the arma- 
dillos inhabit open country within the tropics, though 
some extend into extra-tropical regions. Most prefer 
arid regions, and feed on insects and carrion, together 
with some vegetable matter. The tiny pichiciago or 
fairy armadillo (Chlamydophorus) is found in sandy 
regions in the western part of the Argentine where the 
vegetation consists of cactuses and thorny brushwood. 
It burrows with great rapidity, and is very sensitive 




J 



Fig. 37. Jerboa (Dipus) from Central Asia. 
(From a specimen in the Royal Scottish Museum.) 




Fig. 38. The Egyptian Jerboa (Dipus). The animal is of a greyish- 
sandy colour which renders it very inconspicuous in the desert regions 
in which it lives. (From a specimen in the Royal Scottish Museum.) 



AND DESERTS 135 

to cold or wet. Another species is found in Bolivia. 
The members of the type genus Dasypus are widely 
distributed, being especially common in the Argentine. 
In addition to the protective covering of bony plates, 
they find security from their enemies in their burrow- 
ing habits, and in the fact that they are mostly noc- 
turnal. 

In Africa, where armadillos are completely absent, 
another curious edentate, the aard-vark or ant-bear 
(Orcyteropus) occurs in open regions, and is also of 
burrowing nocturnal habits, though it has no armour 
as the armadillos have. It seems to feed chiefly on 
termites, the so-called white ants. 

Of the marsupials the kangaroos and their immediate 
allies are exclusively confined to the Australian region, 
and there they formed the natural fauna of the savanas 
till the advent of the European with his flocks and 
herds. The kangaroos and wallabies, with the excep- 
tion of the tree-kangaroos already mentioned, are 
ground forms, feeding not only upon grass but also 
upon shoots of bushes and shrubs, or even in the case 
of the larger forms, on leaves, &c., of trees, which they 
reach by standing in the upright position. The tail is 
long and strong. It aids the animal in maintaining 
the upright position, and also in running — that is, in 
leaping. We have already noticed the essential points 
of structure in the kangaroo ; the elongation of the 
hind-limbs, without corresponding elongation of either 
forelimbs or neck, is an adaptive peculiarity which is 
far from uncommon in animals of the open plains. In 
the ungulates the other type of adaptation, that which 
consists in the elongation of both pairs of limbs, and 
therefore necessarily of the neck to permit feeding to 
take place, is the usual one. Just as among the rodents 



136 TROPICAL SAVANAS 

we have various stages in the elongation of the hind- 
limbs, and therefore in the development of the power 
of leaping, so among the kangaroos we have forms like 
the rat-kangaroos (Potorous) in which the elongation 
of the hind-hmbs is much less marked, and which run 
on all fours, and cannot dehver the powerful kicks which 
are so important a part of, e.g., the giant kangaroo's 
means of defence. In the scrub of Queensland the five- 
toed kangaroo {Hypsiprymnodon moschatus) occurs, and 
in the structure and shortness of its hind-feet approaches 
the phalangers, showing that the true kangaroos have 
been evolved in response to the special conditions which 
prevail on the open plains, just as the jerboas on the 
Asiatic steppes have been evolved from ordinary 
rodents, or as the long-legged antelopes and giraffe 
have been evolved from the ancestral short-legged 
ungulates, in response to similar conditions. The nature 
of these special conditions has been already emphasized, 
but we may repeat that if an animal of the open plains 
cannot burrow, or defend itself passively in some way, 
it must be swift to escape its enemies, it must have 
a wide range of vision in order to note their advance, 
it must have acute senses. We saw also in connexion 
with the ungulates that there is a marked tendency to 
reduction in the number of digits, to a fusion of hmb 
bones, and so on, in order to give the necessary strength 
and rigidity for rapid movement. That the same need 
produces the same results is obvious when we note that 
the kangaroo has four toes on its hind-foot instead of 
five, and that of those four two are rudimentary, Uke the 
useless side toes in antelope or deer, though in the 
kangaroo the rudimentary toes have apparently a sub- 
sidiary use, for they are said to be employed in cleaning 
the fur. 



AND DESERTS 137 

In one respect, however, the kangaroo shows a very 
striking contrast to the ungulates. We have noted 
that among the swift ungulates the tendency is for the 
young to be born very fully developed, able after a very 
short period to run by the side of the parent. The 
consequent long period of gestation is dangerous to 
the mother, but has apparently been justified in the 
struggle for existence by the higher survival rate of 
the young. Further, as we may note readily among 
domesticated sheep, the young ungulate, when suck- 
ling, is not allowed by the mother to satisfy its appetite 
completely — it must never be so satiated as to be in- 
capable of flight. In the case of the kangaroo con- 
ditions are very different. The period of gestation is 
very short, and the young one is born in a very im- 
perfectly developed condition, incapable of sucking and 
quite incapable of voluntary movement. It is placed 
by the mother in the pouch with which she is provided, 
and attached to the teat. Milk is then pumped into 
its mouth, by the action of certain of the muscles of 
the mother. Owing to this abundant food, growth is 
rapid, and soon the young one is able to move and 
leave the pouch. It however always returns to it 
on an alarm, and is not able to care for itself 
till it is some eight or nine months old. The mother 
shows great devotion to her young, but if hard pressed 
by dogs she will throw the young one out of the 
pouch into the fern, thus relieving herself of a weight 
which diminishes her speed. The action has been 
variously interpreted. According to some authorities 
the chances are that the dogs will neglect the young 
one and continue to chase the mother, who, if she 
escapes, wiU return to pick up her ' joey '. Others 
regard the action as equivalent to an abandonment of 



138 TROPICAL SAVANAS 

the young. In any case the fact that, with rare excep- 
tions, marsupials have only succeeded in surviving 
in the Australian region, suggests that the placental 
method, that practised by the ungulates, has been 
justified in the struggle for existence as against the 
marsupial method, despite the greater risk to the 
mother before birth and at birth in the former method. 

Only one kangaroo is produced at a birth. This is 
an interesting point, because a reduction in the number 
of young is frequent in animals which must escape 
with their young by flight when threatened, and do 
not attempt to defend themselves nor to hide. A similar 
tendency is well marked in the higher ungulates. But 
it must not be supposed that the kangaroo is entirely 
helpless. In the ungulates we find that, though the 
primary purpose of the elongation of the limb is to 
give swiftness, yet secondarily, e.g. in the horse, the 
powerful hind legs can be used as weapons. Similarly 
the kangaroo can use its long hind-legs to deHver heavy 
blows, capable of kiUing a dog. Like so many denizens 
of open country, the animals are markedly gregarious. 

In regard to the other marsupials we need only note 
that Australia contains various forms shomng special 
adaptations to open grassy plains or desert regions, 
these adaptations exhibiting a curious convergent 
resemblance to those which appear among the pla- 
cental. For example, throughout the greater part of 
Australia the open grassy plains are inhabited by the 
so-called pig-footed bandicoot, a small animal vnth. 
long hind-legs, remarkable in showing an ungulate-like 
reduction in the number of the toes. The fore-foot has 
two functional toes, the hind only one ; the animals 
take both vegetable and animal food. The jerboas and 
jumping mice of other desert regions are represented 



AND DESERTS 139 

in Australia by small marsupials of similar habit, 
notably by Antechinomys laniger, a little jerboa-like 
animal with long hind-legs, a bushy tail, and the habit 
of progressing by jumps. Again, the banded ant-eater 
{Myrmecobius fasciatus) shows the long extensile tongue 
common to ant-eating forms, and is found in sandy 
regions where ant-hills occur. 

Among the inhabitants of savana regions, mention 
must be made of the running birds, which are specially 
adapted to these districts. The adaptations are well 
seen in the African ostrich (Struthio), distributed 
throughout Africa wherever the open sandy regions 
suitable to its habits occur, and found also in Syria, 
Arabia, and Mesopotamia. The great length of the 
legs and of the neck gives the animals a wide range of 
vision (cf. giraffe), the length of the hind-legs and the 
reduction of the number of toes to two gives them 
speed (cf. again the giraffe). Like the large antelopes 
with which the ostriches associate in the southern parts 
of Africa, the ostrich is a social animal, the gregarious 
habit, as in the ungulates, being associated with poly- 
gamy. The males are bigger and stronger than the 
females, and use their hind-legs as weapons when 
attacked. The young are active almost immediately 
after hatching, again recalling the precocious young of 
the ungulates of the steppes and savanas. Like many 
savana animals, ostriches can go without water for a pro- 
longed period, but they drink freely if water is available. 

In South America the place of the ostrich is taken 
by the rhea, which has three toes instead of two, and 
some other structural differences. The habits are some- 
what similar. The birds are chiefly found on the 
pampas, which correspond rather to steppe regions 
than to savanas in the strict sense. 



140 TROPICAL SAVANAS 

In Australia and the neighbouring regions two other 
types of running birds occur, these being the emus and 
cassowaries, which resemble the rheas in having three 
toes, but of these the cassow'aries are forest birds, 
rarely venturing out into the open. The emu, on the 
other hand, is a savana bird, haunting the plains and 
open country, where it eats a large amount of grass. 
The remaining living member of the group, the kiwd of 
New Zealand, like the cassow-ary, is an inhabitant of 
W'ooded districts. 

Another interesting group of birds which inhabit the 
grassy plains of South America, though extending also 
into forest regions, are the tinamus, which show certain 
resemblances to ostriches, but possess the power of 
flight. They strongly resemble game birds in outward 
appearance, being popularly called partridges, but they 
do not fly nearly so well as the game birds, and rise 
with reluctance, preferring to skulk among the long 
grass. The flight is swdft, but cannot be kept up for 
long at a time. 

Among other birds characteristic of savana regions 
mention may be made of the bustards, of which many 
species occur in Africa, just as the common form occurs 
in the steppe regions of Asia. The curious secretary 
bird (Serpentarius secretarius) also, with its long legs, is 
very characteristic of the African savanas. Though 
it is capable of flying well and strongly, it prefers to 
run along the ground, like the ostrich. Its structure 
shows that it is allied to the birds of prey, and the fact 
that the young are very helpless, and are for long 
unable to run upon their elongated legs, suggests that 
the ground-hauntmg habit is a recent acquisition. The 
nest is a huge structure and is often placed in a mimosa 
bush. 



AND DESERTS 



141 




Fig. 39. The Cactus Wren (Gampylorhynchus brunneicapillus), a 
characteristic bird of the desert regions of California and Texas, where 
it builds a complicated nest in cactus bushes. (Photo by the Biological 
Survey, U.S.A.) 

In South America the place of the secretary bird in 
nature is taken by the seriemas, birds apparently 
related to- the cranes, but showing a curiously close 



142 TROPICAL SAVANAS 

external resemblance to the secretary birds. The 
Brazihan seriema (Cariama cristata) haunts open dis- 
tricts with scattered bushes, and is a cursorial bird, 
though it roosts in trees. 

There is nothing very characteristic about the 
reptiles of the savanas and hot deserts, but of the 
numerous hzards which occur there one or two may be 
named as showing interesting pecuharities. In the 
sandy districts of Western and Southern Austraha occurs 
Moloch horridus, a hzard covered with spines and 
tubercles. It Hves upon ants, and has the curious 
power of being able to absorb water through its rough 
skin. This is presumably an adaptation to permit the 
animal to avail itself of the rare showers which fall in 
the desert regions where it hves. 

Somewhat similar in appearance are the ' homed 
toads ' (Phrynosoma) of the desert regions in the 
warmer parts of the United States and in Central 
America. They also have a rough and prickly skin, 
and possess remarkable powers of burrowing. The 
animals are assisted in the process by a curious fringe 
at the sides of the body, and are said to appear actually 
to sink into the sand. They feed upon a variety of 
insects, and in colouring resemble the sandy soil in 
which they hve. In the hot deserts of Northern Africa 
and the adjacent regions occur the skinks (Scincus), 
which are admirably adapted for desert life, their 
bodies enabling them to move through the soft sand 
as fish swim through water. 

The presence of the hzards named, together with 
many others, speaks to the abundance of insects in 
desert and savana regions. These insects do not, as 
a rule, show any very marked adaptations, but we may 
mention the termites, or so-called white ants, as being 



AND DESERTS 143 

very characteristic of the savana regions of Africa and 
elsewhere. 

References. All the books mentioned in the previous chapter as 
giving accounts of African animals, describe the inhabitants of the 
savanas as -vvell as those of the forests. The books mentioned at the 
end of Chapter X also, as giving accounts of the zoological regions, 
describe among others the savana animals. Mention may also be made 
of W. H. Hudson's books, especially The Naturalist in La Plata (London, 
1892) ; and of Tristram's Flora and Fauna of Palestine (London). 



CHAPTER VII 

SPECIAL FEATURES OF ISLAND FAUNAS 

Islands present some interesting features as regards 
their animal life which makes them worthy of special 
study. We have already seen that mountain areas have 
special types of animals, because they form isolated 
regions cut off by the physical conditions from the 
neighbouring districts. The special conditions in their 
case include both climate and topography, and in what- 
ever region of the globe the mountains occur, if they are 
greatly elevated, the climatic conditions are similar. 
Islands are regions cut off from neighbouring regions 
by the sea, which forms a barrier to the passage of all 
but the marine and the flying animals. Even to flying 
animals a large expanse of sea may constitute a for- 
midable barrier, save in the case of those with excep- 
tional powers of flight. The consequence is that island 
faunas form a whole, and can be studied with much 
more ease than the animals of any other natural region. 
The question whether a particular animal does or does 
not occur in an island is merely a question of observa- 
tion ; while that as to whether a form found on a 
mountain does or does not constitute part of the moun- 
tain fauna is a much more delicate one, involving an 
elaborate process of reasoning. In the one case a 
gradual migration with concurrent adaptation is pos- 
sible from plain to mountain or vice versa, but no such 
slow migration is possible in the case of islands. 

On the other hand, it is to be noted that while 



ISLAND FAUNAS 145 

mountain animals, like those of steppes or forests, are 
exposed to virtually uniform conditions of climate, &c., 
no such uniformity exists in the case of islands. We 
speak, it is true, of insular climates, meaning that the 
proximity of the sea has a certain moderating effect, 
more especially if there is a large expanse of ocean all 
round, or if the prevailing winds blow from such an 
expanse. But even within the same island there may be 
great variations of climate, and there may be almost all 
types of surface — mountain, wood, steppe, tundra, and 
so forth. Thus, while the inhabitants of islands may 
be readily counted and classified, and form a statistical 
unity, they do not form a biological unity in the sense 
that the animals of the other natural regions do, and 
there are few general statements which can be made 
of them as a whole. 

The special features of island faunas may best be 
illustrated by a few examples, and we may begin by 
a consideration of the Galapagos Islands, an interesting 
group which has been studied by various naturahsts, 
including Darwin. 

This archipelago consists of a group of islands lying 
some seven hundred miles off the coast of Ecuador, 
and on the equator. They are of volcanic origin, the 
surface being covered with extinct craters, and are 
placed upon a submarine bank, which rises steeply 
from the depths of the Pacific. The climate is singu- 
larly cool for the position, this being due to the fact 
that the islands are washed by the cold Humboldt 
current. In the lower regions of the islands the rain- 
fall is markedly deficient, rain only falling in small 
amounts in the earlier months of the year (February- 
May). Here the vegetation is scanty, and xerophytio 
in character, the most important plant from the 

1404 K 



146 , SPECIAL FEATURES 

economic point of view being the archil lichen from 
which the dye called Htmus is obtained. Darwin 
describes this lower zone as uninviting in the extreme, 
the scanty brushwood leaving the black basaltic lava 
exposed, and giving the district the appearance of an 
iron-smelting region in the ' black country ' of England. 
But the clouds hang low, and above an elevation of 
about eight hundred feet not only is there abundant 
rain during the rainy season, but even at other seasons 
a constant mist keeps the vegetation fresh. The plants 
of the two regions differ fundamentally, and in the 
upper cultivated plants from many cKmates thrive. Of 
the native vascular plants, about one-haK are pecuUar 
to the islands. The group consists of five principal 
and eight small islands, with a total area of nearly 
3,000 square miles. The hills range in height from 
3,000 to 4,000 feet. The more conspicuous bushes and 
trees are species of euphorbia, cactus, and acacia, 
so that the islands generally resemble savanas and 
desert regions in their vegetation. Palms are entirely 
absent. 

Turning now to the fauna, we find that mammals are 
practically absent. There are two mice, but of these 
one belongs to the widely distributed genus Mus, and 
has doubtless been introduced ; the other belongs to 
a South American genus (Hesperomys), and has also 
possibly been introduced. That there is nothing in the 
conditions of the islands to prevent the existence of 
even large herbivorous mammals is, however, shown by 
the fact that goats, pigs, horses, &c., introduced by 
man, have become wild, and have multiplied exceed- 
ingly. 

The birds present some interesting features. About 
seventy species, according to Wallace, have been 



OF ISLAND FAUNAS 147 

obtained in the islands, and of these forty-one, or con- 
siderably more than half, are peculiar to the islands, 
not being found elsewhere. Most of those which are 
not peculiar are birds with considerable powers of 
flight, capable of travelling great distances. Of the 
true land birds all but one are peculiar, and this one 
is the common rice-bird {Dolichonyx oryzivorus), which 
occurs throughout the whole of the American continent. 
This bird is markedly migratory, spending its winters 
in the West Indies and Central America, and travelling 
northwards in vast numbers to breed and spend the 
summer in the northern United States and Canada. 
There is, therefore, nothing improbable in the supposi- 
tion that stragglers from the migrating flocks reach 
the Galapagos Islands from time to time, and so pre- 
vent an island type from establishing itself. The other 
land birds of the islands show, as Wallace points out, 
all gradations from close resemblance to forms occurring 
elsewhere to generic difference. Thus the archipelago 
contains a special owl — Asio galapagensis — but this is 
very nearly related to the widely distributed short- 
eared owl {Asio hrachyotus). On the other hand, among 
the finches peculiar genera occur, e. g. Geospiza, related 
to genera of restricted range found on the continent 
of South America. Again, though the islands are 
relatively so near together, a peculiar genus may be 
represented by three different species on as many 
different islands. This is well exemplified in the case 
of the honey-creepers of the genus Certhidea, the three 
species of whicli occur on different islands. 

The reptiles of the islands are especially remarkable. 
The giant tortoises have long been famous, and give 
the islands their Spanish name. Such giant tortoises 
occur only on islands, beiag found in certain islands in 

K 2 



148 SPECIAL FEATURES 

the western Indian Ocean, and in the Galapagos archi- 
pelago. In addition to their large size the animals have 
as special pecuHarities the fact that they show much 
individual variation, and tend also to spht up into 
species, different species occurring on adjacent islands. 
No small tortoises occur on the islands containing these 
large forms. A final peculiarity is that the bony cara- 
pace tends to be reduced in thickness, perhaps because 
tiU man came the animals had few enemies. The diet 
is exclusively vegetarian, and the animals occur in both 
the upper well-watered region and in the lower arid 
region. The fact, however, that they drink greedily, 
and are fond of wallowing in muddy water, suggests 
that they are not native to arid regions. Darwdn gives 
an interesting description of the long journeys made by 
the low-ground tortoises to the springs of the upper 
region, in order to obtain water. The cactuses of the 
arid regions form a favourite food plant. The exact 
number of species is a matter of doubt, owing to the 
individual variability already mentioned. 

In addition to the giant tortoises, the Galapagos 
possess both lizards and snakes. Two of the lizards 
are very large and of very peculiar habits. One {Cono- 
lophus svbcristatus) is found only on the central islands 
of the archipelago, and occurs both in the upper and 
lower regions, but more abundantly in the latter. The 
forms from the arid districts, however, do not travel 
upwards to the springs to drink, and are far more 
numerous than the upland forms. As the diet of these 
lizards is quite similar to that of the tortoises, it would 
seem that originally the lizards inhabited the arid 
ground, and the tortoises the damp upper regions, but 
each has become partially adapted to the territory of 
the other. The lizards reach a length of a yard, and 



or ISLAND FAUNAS 149 

liave stout heavy bodies. They are very partial to 
cactuses, but also climb the acacia trees to feed upon 
the foUage. 

Closely related to Conolophus, and therefore like it 
one of the iguana family, is the marine lizard Amhly- 
rhynchus cristatus. It also is entirely peculiar to the 
islands, and is the only Kzard known which is marine 
in habitat. It inhabits the shores of most of the islands, 
and feeds upon seaweeds which grow below tide mark, 
and, as Darwin proved, it can tolerate prolonged im- 
mersion without any ill effects. It will be recollected 
(cf. p. 116) that the typical iguanas are forest animals. 
The exceptional conditions to which the forms in the 
Galapagos Islands are exposed has made it necessary 
for these to adopt modified habits. 

The family Iguanidae is further represented in the 
islands by various peculiar species of the genus Tropi- 
durus, other members of which occur on the continent 
of South America. Various species of geckoes belong- 
ing to the widely distributed genus Phyllodactylus also 
occur, most of these being pecuhar to the islands. 
There are also two snakes, both being nearly allied to 
South American forms. 

Amphibians are entirely absent. Of the inverte- 
brates the insects are few in number, but show the same 
characters as the other kinds of animals. In other 
words, most of the species and many genera are peculiar, 
and the forms tend to have a Hmited distribution 
among the islands, very few being found in all the 
islands. Further, there are many wingless forms, 
a common feature in island insects. 

It is not necessary to describe the fauna of other 
islands of the same type as the Galapagos archipelago 
in detail, for the general characters are the same in 



150 SPECIAL FEATURES 

all. Islands which do not he very near a continent, 
and are separated from the nearest continent by 
deep water, that is, do not lie upon the same con- 
tinental shelf as the continent, show great general 
similarity as regards their fauna. In such islands there 
are no indigenous land mammals, often with the doubt- 
ful exception of mice and rats, animals readily intro- 
duced by man. Amphibians are also absent, a fact 
readily explained when we recollect that both the eggs 
and adults are very intolerant of salt, and therefore 
could not be readily transported across sea-water by 
floating logs of wood or any similar means. In such 
islands generally the commonest land forms are birds 
and invertebrates, especially insects and land shells. 
These in all cases tend to run into local races, due 
apparently to the isolation of the stock. Further, fly- 
ing forms tend to lose their wings or to possess only 
limited powers of flight. This is very marked in some 
birds, thus the flightless dodo, the solitaire, the kiwi of 
New Zealand, and so forth are all inhabitants of islands. 
It is noticeable that the power of flight tends specially 
to diminish in animals found in islands much exposed 
to hurricanes, for here even short flights might expose 
the animals to strong winds, which would sweep them 
out to sea, and thus destroy them, while those which 
flew little or not at all would be more likely to breed 
and continue their own type. 

Reptiles are not very frequent in islands separated 
by deep water from continents, and the presence of 
the large tortoises in the Galapagos Islands is held by 
some to indicate a connexion, at a remote period, with 
the continent of America. Wallace, on the other hand, 
believes that the ancestors of these forms were acci- 
dentally introduced, possibly on floating timber. 



or ISLAND FAUNAS 151 

Generally the fauna of islands like the Galapagos, called 
oceanic by Wallace, is such that its members may 
be supposed to have been, at least to a large extent, 
accidentally introduced — by storms carrying winged 
animals out of their usual course, or by mechanical 
transportation on floating wood, &c. Incidentally we 
may note that the absence of mammals on oceanic 
islands has often important human consequences, for 
the paucity of sources of animal food tends to make 
their human inhabitants cannibals. 

As contrasted with oceanic islands we have the 
islands which are obviously merely separated portions 
of the adjacent continent upon whose continental shelf 
they stand. A good example is furnished by the British 
Isles, whose fauna is very similar to that of the adjacent 
continent, but shows impoverishment in several re- 
spects, apparently as a result of the glacial period. 
As Ireland was apparently cut off from the continent 
before Great Britain, and at a stage when many of the 
animals driven south by the ice had not had time to 
recover lost ground, we find that its fauna is poorer 
even than that of the larger island. The following 
figures, quoted from Wallace, will help to render the 
above statements more precise. Scandinavia possesses 
about 60 species of mammals, Great Britain 40, and 
Ireland 22 ; Belgium has 22 species of reptiles and 
amphibia. Great Britain 13, and Ireland only 4. The 
question as to the number of pecuHar forms in the 
British fauna has been actively debated. That the 
red grouse (Lagopus scoticus) of the northern regions is 
pecuhar is generally admitted, though it is nearly allied 
to the willow grouse of Scandinavia. We have also 
some peculiar fresh-water fish, most of which occur in 
lakes. The differences are, however, not very striking, 



152 SPECIAL FEATURES 

and are no doubt due to the fact that the chances of 
the fish of one loch interbreeding with those of another 
are very small. There are also a considerable number 
of peculiar species or varieties of insects, but nothing 
comparable to the differences which separate the 
animals of the Galapagos Islands from those of the 
adjacent mainland. To add point to the contrast we 
may note that the area of the British Isles is in round 
numbers, 121,500 square miles, as contrasted with the 
3,000 square miles of the Galapagos Islands. Suchislands 
as the British Islands are called by Wallace continental, 
in contrast with the oceanic type. 

One more example of an island fauna may be given. 
In this case we shall take Madagascar, which is of the 
continental type, but is separated from the continent 
of Africa by a channel so deep and wide that it must 
be supposed that the connexion between the two was 
broken at an extremely remote period. The total area 
of this large island is nearly twdce that of the British 
Isles, and there is much forest. The fauna is remark- 
ably rich, and is as markedly characterized by the 
animals it includes as by those of which it is devoid. 
Thus the island has no monkeys in its wide tropical 
forests, but has some thirty-three species of lemurs, 
which constitute half the mammahan population 
of the island. Insectivores are fairly numerous, and 
include in the tailless hedgehogs (Centetes) primitive 
forms whose nearest aUies appear to be some shrews 
in the West Indian Islands. There are not many 
carnivores, and no true cats, but in addition to eight 
civets there is a relatively powerful animal called 
Cryptoprocta, about the size of a common cat, which 
belongs to the civet group. There are few rodents, and 
the enormous wealth of large ungulates, which is so 



OF ISLAND FAUNAS 153 

characteristic of the continent of Africa, is here scarcely 
suggested, for that important order is only represented 
by a river-hog and a subfossil pygmy hippopotamus. 
Both the species and genera of mammals are strikingly 
peculiar ; thus it appears that of the twenty-four 
mammalian genera of Madagascar only two occur in 
Africa. 

The birds are not quite so pecuhar, but they also 
show, though to a less degree, the same feature of the 
absence of the African forms which would be expected, 
and the presence of primitive or peculiar forms. Among 
both snakes and lizards we find the peculiar feature 
that American forms are represented ; among the lizards 
by two Iguanidae, otherwise peculiar to America. The 
other lizards are mostly peculiar members of African 
famihes, but a special feature is the number of 
chameleons, and the absence of the monitors, which 
are abundant in Africa. There are no poisonous 
snakes. The amphibians are remarkable, for they 
present affinities both with the Indian region and with 
South America. The beetles, again, show affinities with 
those of India, Australia, and the Malayan region. 

Without considering in detail the various questions 
raised by these pecuHarities, it may be sufficient to say 
generally that Madagascar was formerly connected to 
Africa, and perhaps also through a chain of islands 
to India. The connexion was broken before the higher 
forms of life, e.g. the monkeys, the higher ungulates, 
&c., had penetrated Africa, and consequently the 
original mammalian and other fauna of Madagascar 
was primitive in type. Saved from the competition of 
higher forms by isolation, and favoured by the abundant 
food, the absence of enemies, and the great forest area, 
many forms, notably the lemurs, have reached a high 



154 SPECIAL FEATURES 

degree of specialization along their own lines, and have 
evolved in many different directions. 

If we sum up the more important general points in 
regard to island faunas, we may note first that Wallace's 
distinction into oceanic and continental islands is not 
of very great practical importance, because the pro- 
gress of geology, since the classification was laid down, 
has made it difficult to apply. It involves a conception 
of the permanence of ocean basins which is not now 
generally accepted. Thus, while Wallace names the 
Galapagos group as a characteristic oceanic group, 
others beheve that the presence of giant land tortoises 
is in itself a proof of a former land connexion. For 
our purpose then it is sufficient to recognize the follow- 
ing three conditions : 

1. When an island has never had a connexion with 
a continent, e. g. many coral and volcanic islands, or 
has only had such a connexion at a geologically remote 
period (Galapagos?) before the higher forms living at 
the present day had originated, or before they had had 
time to become widely distributed, its fauna contains no 
mammals, no amphibia, (1) no reptiles, or (2) reptiles of 
a very primitive type, or (3) such as could be accident- 
ally carried by floating wood, &c. The most important 
members of its fauna will be birds, insects, and land 
shells. Owing to the isolation the animals will tend to 
exhibit special pecuharities, fitting them for their 
habitat. Among flying forms the conditions favour 
those in which the power of flight is moderately de- 
veloped, or has disappeared. Examples of such islands 
are the Azores, the Bermudas, St. Helena, the Sand- 
wich Islands, &c. Where such islands have had a 
continental connexion, this must have been prior to 
the deposition of the lower Tertiary beds, for at this 



OF ISLAND FAUNAS 155 

time mammals were evolving rapidly and spreading 
widely. 

2. When an island has been separated from adjacent 
land masses for a moderately long time, i. e. since the 
middle of the Tertiary period, it will tend to have 
a rich fauna, including representatives of all the chief 
classes and phyla, but the more modern classes will be 
represented by primitive forms, their primitiveness 
depending on the length of the period during which the 
island has been isolated. Of such islands Madagascar 
and the adjacent islands of the Indian Ocean are good 
examples. 

3. When the separation of an island from the adjacent 
continent has taken place within geologically recent 
times, i. e. in the Pleistocene or Post-Pleistocene period, 
the fauna will be in all essentials similar to that 
of the adjacent land mass, though minor differences 
may occur. Examples are the British Isles, Japan, 
Borneo, Java, &c. 

In other words, the most satisfactory classification 
of islands from the point of view of their fauna depends 
upon the approximate length of time since which they 
have been isolated. 

References. Wallace's Island Life (second edition, London, 1892) is 
the classical work dealing with the subject, which is also discussed to 
a minor extent in the same author's Darwinism. A very interesting 
account of the Galapagos Islands will be found in Darwin's Journal of 
Researches into the Natural History and Geology of the Countries visited 
during the Voyage of the ' Beagle ' (London, 1843). The subject is also 
fully treated in Beddard's Text-hook of Zoogeography (Cambridge, 1895). 
See also Dobson's, On Some Peculiarities in the Geographical Distribution 
and in the Habits of certain Mammals inhabiting Continental and Oceanic 
Islands {Ann. Nat. Hist. xiv. 1884). 



CHAPTER VIII 

THE DISTRIBUTION OF ANIMAL LIFE 
IN THE SEA 

While, as we have seen in the previous chapters, 
the natural regions of the land more or less grade 
into one another — savana, for example, passing into 
savana wood, and savana wood into forest, it is very- 
much easier to separate the oceans into natural regions, 
for here the divisions are relatively sharp. The two 
great conditions which influence the type of animal to 
be found within any part of the sea are, first, the pres- 
ence or absence of hght, and, second, the presence or 
absence of a substratum. At the margin of the sea, where 
the light penetrates to the bottom, we have the httoral 
area, peopled by littoral organisms. All these organisms 
agree in that, in structure or in habit, they show adapta- 
tions to the two striking features of the area. Thus 
a sea anemone, fixed to a rock and containing symbiotic 
algae, is obviously adapted for life in a region where 
a substratum is present, and where hght penetrates. 
A plaice, so shaped that it is adapted for lying on 
a sandy surface and bearing well-developed eyes, is 
similarly fitted. But the dependence of a mud-haunt- 
ing animal feeding upon minute algae upon httoral 
conditions is no less real, if less apparent, for land- 
derived mud only accumulates off shores, and the 
minute algae must have light before they can five. 

In the open water occurs another group of organisms, 



ANIMAL LIFE IN THE SEA 157 

constituting the 'pelagic forms, which require no sub- 
stratum, but for the most part demand hght, and usually 
display sensitiveness to it. Finally, at the bottom of 
the ocean, in the great depths, we have forms entirely 
independent of sunlight, but directly or indirectly 
dependent upon the presence of a substratum. These 
are the abyssal animals, whose existence was first fully 
demonstrated by the Challenger expedition. 

We can thus divide the inhabitants of the ocean into 
three well-defined classes, each class showing adapta- 
tions to a natural region. These three groups are 
(1) the littoral, (2) the pelagic, and (3) the abyssal, 
each of which we must consider separately. As we 
shall see, the members of the different groups do not 
necessarily restrict themselves throughout their whole 
life history to one of the natural regions. It is, for 
example, very common to find that littoral forms have 
pelagic larvae, or pelagic stages in their Hfe-history, 
able to take advantage, for purposes of distribution, 
of the many currents which influence the surface waters 
of the sea. 

(1) The littoral zone extends outwards from the 
margin of the land to the edge of the continental shelf, 
or roughly to the one hundred fathom line. Beyond 
this line the sea-bottom usually slopes rapidly in the 
Continental Slope to the great depths, where the 
littoral animals are replaced by the abyssal ones. 
Shallow seas, such as the North Sea, contain only 
littoral and pelagic animals. Throughout its exten- 
sion the littoral area is characterized by its great 
wealth of food, and its great variations in the physical 
conditions. The basal sources of food are here three : 
(1) the waste of the land, (2) the fixed algae of the 
shore rocks, (3) the minute floating algae or phyto- 



158 THE DISTRIBUTION OF 

plankton. The importance of the waste of the land may 
be realized if we think of the number of marine animals 
which find food in the mud-deposits which accumulate 
round the mouths of rivers and estuaries. If the water 
be fairly clear, such estuaries are specially favourable 
to shell-fish like mussels and oysters ; to many marine 
worms, which in their turn feed many fishes ; to many 
small Crustacea, which also feed fish ; and so forth. 
This land-waste has only a limited seaward extension, 
and is not available as a source of supply either for the 
pelagic or for the abyssal animals. 

The fixed algae can only grow where some firm sur- 
face to which they can attach themselves exists, and 
where the sunlight is strongly felt. They are therefore 
limited to the margin of the lands, but there form rich 
feeding-grounds. The Laminarian zone, which lies just 
beyond low-tide mark, has always been known as 
a rich coUecting-ground. It contains many small forms 
— Crustacea, molluscs, worms, coelenterates, and so 
forth — perfectly adapted to life among the long brown 
fronds and about the branching roots. At high tide 
this zone is covered with a sufficient depth of water 
to be available as a pasture ground even for the larger 
fish, and here therefore shore animals cluster, and the 
fisherman reaps rich harvests. 

Finally, in the shore waters minute algae swarm. 
In their habits and adaptations most of these are 
pelagic, that is apparently independent of the presence 
of a substratum, but the fact that there is considerable 
difference between the phytoplankton of the shore 
water and of the open sea, suggests that these forms 
are in some way indirectly affected by the proximity 
of the sea-floor, or by the waste of the land. Diatoms, 
especially, which are eagerly consumed by many 



ANIMAL LIFE IN THE SEA 159 

animals, are represented in the shore waters by many 
species — by more than in the open ocean. But, it 
may be asked, if these algae have no attachment to 
a substratum, how do they contrive to remain in 
the shore waters, in spite of currents and tides which 
must tend to sweep them seawards ? The answer 
is apparently that myriads are so swept out into 
the ocean, but there they degenerate, and probably 
do not live long. Produced in the shore waters, their 
destiny may be to serve as food for the pelagic animals 
of the open seas, but they no more form a true part 
of the life of the pelagic area than does that shore- 
born weed which floats at the surface of the Sargasso 
Sea for a period, ere it perishes and is replaced by new 
fragments torn off by the currents. 

Of the physical peculiarities of the littoral area the 
constant movement of the waters is characteristic. 
Tides and currents, in aU the open seas, ensure that no 
stagnation shall occur, and thus keep the water sweet, 
and bring constant supplies of food and oxygen. It is 
this constant movement which helps to give the shores 
of the oceans so much richer a fauna than the shores of 
lakes, or of enclosed seas like the Mediterranean or 
Black Sea. The constant movement brings with it 
also a danger, whose influence is manifest in several 
ways. Some of the shore forms are swift swimmers, 
strong to stem the tide, and yet, notwithstanding their 
strength, the shore naturalist knows that off many 
coasts he is sure of a rich harvest when wind enforces 
tide or current, for the beach at certain seasons is 
strewn with flotsam and jetsam. Many shore fish, the 
strong cuttles among molluscs, powerful forms like 
porpoises and dolphins and even whales — there are 
times when the strength of these avails them nothing 



160 THE DISTRIBUTION OF 

against the movement of the waters, and they are found 
dead or stranded on the beach. 

The weaker abandon the attempt to struggle against 
the waters — the lumpsucker and the gobies among fish, 
the limpet among molluscs, the acorn shells and bar- 
nacles among Crustacea — these do not attempt to resist 
the tides, but cling tight and allow the danger to pass. 

Another danger, quite as real, though not so obvious, 
which the shore forms must guard against is the con- 
stant change of temperature and of salinity in the sea 
water, which is characteristic of the shore. The 
temperature of the oceans varies much, and is in- 
fluenced by local causes, but the shore waters especi- 
ally are greatly affected by the variations in the tempera- 
ture of the land, that is by latitude. In tropical waters 
the range of temperature is small (about 10° F.), and 
the mean temperature is high (about 80° F.). In polar 
waters, while the range is similarly small, the mean 
temperature is low (about 28° F.). Between the two, 
in temperate regions, the range is considerable, while 
the mean is neither high nor low. Nowhere, of course, 
can the ranges of temperature in the sea be compared 
with those on land, owing to the high specific heat of 
water. We find, however, that very many land animals, 
for instance all the warm-blooded ones, have a heat- 
regulating mechanism, whereby they can adjust them- 
selves to changes of temperature. Such a mechanism 
is absent in all sea animals except those (e. g. whales, 
&c.), who are descended from terrestrial ancestors. 
According as they can or cannot tolerate variations 
in the temperature of sea water, sea animals may 
be divided into eury thermal and stenothermal forms. 
The former are tolerant of great variations, the latter 
are rapidly killed by them. Speaking generally, the 



ANIMAL LIFE IN THE SEA 161 

littoral animals of temperate latitudes must be eury- 
thermal, while those of tropical and of polar seas may 
be stenothermal. As the actual temperature in the 
case of many stenothermal animals seems to matter less 
than its constancy, the temperate zone must form 
a barrier between the animals of the two other zones, 
and more or less prevent their mixing. Further, as 
sudden changes are always more dangerous than gradual 
ones, the contact of a cold current with a warm one 
seems often to lead to a great destruction of animal 
life, though this perhaps affects pelagic animals more 
than littoral ones. 

Variations in the salinity of the water seem to have 
similar effects, and Hjort states that of the seventeen 
species of the cod family found in the North and 
Norwegian Seas, each one seeks out a special spawning- 
ground, having its characteristic depth, temperature, 
and salinity, a fact which may be partly due to greater 
susceptibility of the larvae than of the adults to minor 
variations in pressure, temperature, and salinity. 

Something must now be said as to the characters of 
shore animals. In the chapter on the tundra we men- 
tioned some of the common forms to be found in Arctic 
regions, and to that account some more general state- 
ments may be added. Of the marine mammals we 
must regard all the seals and the walrus as littoral 
forms, for though many show a perfect mastery of the 
water, all come on shore for breeding purposes, and 
thus are dependent on a substratum, at least at certain 
seasons. In addition to the seals already mentioned, 
we have the true fur-seals (Otaria), which occur in the 
north, outside the Arctic area, and the many seals of 
the Far South, such as Weddell's seal {Leptonychotes 
weddelli), Ross's seal {Ommatophoca rossi), the crab- 

1404 L 



162 THE DISTRIBUTION OF 

eating seal {Lobodon carcinophaga), the sea-leopard 
{Stenorhynchus leptonyx), which all occur in the region 
of ice-pack, while the sea-elephant {Macrorhinus leo- 
ninus), and the southern fur-seal [Otaria jubata) occur 
in sub- Antarctic seas as well as elsewhere. The fact 
that aU these different kinds of seals tend to occur in 
cold regions cannot be ascribed wholly to deliberate 
choice on their part, for the young of all are born on 
the land, and the animals seek out places as free as 
possible from molestation, which are more frequent in 
polar seas than elsewhere. Since man joined their 
enemies many species are being driven further and 
further back into the inaccessible parts of the polar 
seas, or have been virtually exterminated. 

The seals, walrus, and sea-otter, the last named 
being a fur-bearing animal found off rocky coasts in 
the North Pacific, are all carnivores which have taken 
recently to the aquatic life, and are still bound to 
terra firma at the breeding season. There are, how- 
ever, two orders of mammals whose members are 
entirely aquatic, their young being born under water. 
These are the Cetacea or whales and dolphins, and 
the Sirenia or sea-cows. The former are powerful 
swimmers, and are pelagic. Their only connexion with 
shore is that the greater abundance of fish in shallow 
water brings many of them to the vicinity of sub- 
marine ' banks ', while the whalebone whales haunt 
relatively shallow water in high latitudes, because of 
the abundance of small marine organisms there. 

The Sirenia include only two living animals, the 
dugong (Halicore) found in the Pacific and Indian 
Oceans, and extending southwards to the shores of 
Australia, and the manatee (Manatus) which lives in 
the estuaries of the great rivers M^hich flow into the 




Fig. 41. The shore of Copper Island, in the Bering Sea, showing a Rookery of Fur-seals. 
The seals prefer the rocky portion of the beach close to the water, and only the weaker 
forms, unable to obtain a foothold there, haunt the smooth ground at the back of the 
rookery. {Photo by Prof. D'Arey W. Thompson.) 




O ^ 



£«: 



^ 



ANIMAL LIFE IN THE SEA 163 

tropical part of the Atlantic, and in shallow bays or 
lagoons. Though both spend their whole life in the 
water, and are helpless outside it, yet both are definitely 
littoral, for they feed upon the large algae, and could 
therefore find no food in the open sea. The manatee 
apparently takes a large variety of aquatic plants in 
addition to algae. The animals are not nearly such good 
swimmers as the Cetacea, and their heavy bodies and 
massive bones fit them for life near the bottom. The 
hind-legs are entirely absent, but the fore-limbs may 
touch the ground as the animals swim leisurely along 
the bottom, and are also used in pushing food into the 
mouth, and in carrying the young, which are suckled 
above water. 

Of the littoral birds perhaps the most interesting are 
the flightless penguins, which present the same features 
as the seals in that, though pelagic for much of the year, 
and having a perfect mastery of the water, they must 
come on shore for breeding purposes. The absence of 
any carnivorous land mammals in the Antarctic area, 
and its inaccessibility, make it a perfect paradise for the 
penguins, who resort to its rocks and beaches in millions 
to breed, and have been described by all the Antarctic 
expeditions (see Fig. 44). Quite comparable in habits, 
though not related, was the extinct great auk (Alca 
impennis) of the shores of the North Atlantic, which 
was similarly incapable of flight, and fell an easy 
victim to man during the breeding-season. 

Of the other birds which feed in the sea and frequent 
it, some, like certain of the seagulls, forsake it at the 
breeding-season for inland regions. Others, like little 
auks, guillemots, puffins, gannets, and so forth, breed 
on the shore, choosing cold or inaccessible regions 
for the purpose. Of the various adaptations to such 

L 2 



164 



THE DISTRIBUTION OF 



breeding-places which they show the commonest is the 
pointed egg, which does not roll ofE the rocks readily, 
while the eggs themselves are frequently protectively 




Fig. 43. Kittiwake Gulls nesting on basaltic pinnacles on Majj^Island, ' 
in the Firth of Forth. {Photo by Mr. George' West.) 

coloured, except where, like those of the puffin, they 
are concealed in holes. 

Of the reptiles relatively few are marine animals, 
the habit being most frequent among the turtles and 




.3 



(It 



ANIMAL LIFE IN THE SEA 165 

tortoises (Chelonia). The very curious leathery turtle 
(Sphargis coriacea) is apparently found in all tropical 
seas, but it is either very rare or its habits make it 
infrequently seen and caught. It is a large animal, 
sometimes measuring six and a half feet long, and feeds 
exclusively on fish, molluscs, and Crustacea. The limbs 
are turned into paddles, the anterior ones being very 
long, and the animal is apparently pelagic in habit and a 
swift swimmer, though it is tied to the land by the need 
of breeding there. The eggs are laid on sandy shores, 
especially on the eastern side of tropical America. 

The green or edible turtle of commerce {Chelone 
mydas) is also marine, but the fact that it is vegetarian, 
feeding upon algae and other aquatic plants, binds it 
closely to the shore, though the animals are good 
swimmers. As usual the eggs are laid on sandy beaches. 
Another species of the same genus is the hawksbill 
turtle {Ch. imbricata), which supplies the tortoiseshell 
of commerce, and is carnivorous, feeding upon fish and 
molluscs. Both these forms have a wide distribution 
in warm seas, while the loggerhead {TTialassochelys 
caretta) extends into the Mediterranean and Bay of 
Biscay. This is a carnivorous form, and occurs hun- 
dreds of miles from land, floating on the surface. Again, 
however, it must approach the land at the breeding- 
season. 

We have already spoken of the marine lizard of the 
Galapagos Islands (p. 149), and there are also sea- 
snakes (Hydrophis) similarly adapted for life in the 
sea. These animals, which are especially found off the 
coasts of the Indian Ocean, have compressed swimming- 
tails, and feed upon fish. As in the case of so many 
forms which have secondarily returned to the aquatic 
life, their dependence on the land is especially shown 



166 THE DISTRIBUTION OF 

at the breeding-season, for the gravid female must come 
on shore to produce her young. For this purpose she 
visits the shores of low islands, where she may be found 
coiled up among the rocks. 

The fact that amphibians have unprotected skins, 
through which salt can pass very easily, makes them 
intolerant of its presence, and we have thus no marine 
amphibia. 

Littoral fishes are many, and range from forms like 
the lumpsucker, the gobies, the sea-horses, the pipefish, 
and so forth, which inhabit rocky pools within or close 
to tide marks, through forms hke plaice, dabs, turbot, 
skate, fishing frogs, &c., which haunt the sandy bottom, 
their shape fitting them for Hfe here, to forms Hke cod 
and haddock, whose chief adaptation to littoral life is 
that they are ground feeders, depending upon animals 
like hermit crabs, marine worms, shellfish, &c., which 
only occur on the bottom. 

It is a curious illustration of what has been already 
said as to the tendency to change from the pelagic to 
the Httoral habitat during the life-history, that the 
httoral cod and haddock should have floating or 
pelagic eggs, and should in their early hfe haunt the 
surface, often seeking shelter within the bells of the 
pelagic jellyfish, while the herring, which in adult 
life is a pelagic fish, feeding on free-swimming Crus- 
tacea, has heavy or demersal eggs, which sink to the 
bottom. 

The tunicates or sea-squirts mostly attach them- 
selves to the sea-bottom, but have pelagic free-swim- 
ming larvae. 

Of the molluscs a vast number are littoral forms. 
Many cuttles cower down on the sea-bottom waiting 
for their prey, or clamber over the rocks by the aid of 



ANIMAL LIFE IN THE SEA 167 

their sucker-bearing arms. The flat creeping surface 
which forms the foot in most gastropods, such as peri- 
winkles, whelks, and so forth, indicates the dependence 
of these animals upon a substratum. The bivalves 
often live buried in the mud, like Mya and Lutraria, 
or in sand like cockles, or they are attached by a byssus 
or tuft of silky threads like the common mussel, or they 
bury themselves in the substance of the rocks Hke 
Pholas and Saxicava. Many of these forms, however, 
have pelagic larvae. 

While many of the Crustacea are pelagic, like the 
copepods or water-fleas, and various forms of prawns, 
others, hke crabs, are adapted for life on the bottom. 
Indeed, we can trace among the shore Crustacea the 
gradual acquirement of the ground-haunting habit, 
leading by various stages from a form with the power 
of swift swimming like the lobster, to forms which can 
only walk like the crabs, these showing many very 
interesting adaptations to their relatively sedentary 
hfe. 

The majority of the annelid worms are httoral, 
relatively few being adapted to the pelagic Hfe. Curiously 
enough, however, not only have most of them pelagic 
larvae, but certain forms become temporarily pelagic at 
the breeding-season. The most striking example of this 
is the palalo worm of various islands in the Pacific. 
This worm Uves among the coral reefs, but at certain 
seasons a portion of the body containing the sexual 
elements is Hberated, and leads a brief free-living life 
at the surface, before death occurs. The liberation 
of these sexual portions takes place at night, simul- 
taneously in thousands of worms, so that the whole 
surface of the water becomes filled with the animals, 
which off Fiji, the Friendly Islands, and elsewhere, 



168 THE DISTRIBUTION OF 

are eaten by the natives as food. The portion of the 
worm which remains behind in the coral reefs regener- 
ates the missing segments, and a year later the process 
is repeated. A similar process is suggested in certain 
British annehds, and is a device to ensure that the 
eggs are carried to a distance from the parent. 

The littoral annelids show many beautiful adapta- 
tions to shore hfe. We can only name the sea-mouse 
(Aphrodite), which Hves buried in mud ; Serpula, 
which secretes Hme from the sea water and fashions 
a tube, which it attaches to rocks or to the hard parts 
of other animals or to weed ; Terebella, which builds 
up tubes from the sand, and implants them deeply in 
the sand so that it is safe from the wash of the waves ; 
a Nereis, which lives inside the shell inhabited by 
a hermit crab, and thus finds protection from its 
enemies, and so forth. Very many of these annelids 
are greatly prized as food by fishes, and it is their 
abundance in the shore waters that attracts so many 
fish there. 

Very many of the echinoderms also are httoral, and 
manifest obvious adaptations to this mode of hfe. The 
sea-urchins burrow in the sand or mud, or else chmb 
about the rocks by means of their suctorial tube feet. 
Starfish and brittle-stars similarly clamber over the 
bottom, while the holothurians either live buried in 
the sand or attach themselves by their tube feet. 

Not a few unsegmented worms are littoral, a pretty 
example being the turbellarian called Convoluta, which 
possesses symbiotic algae, a common feature of shore 
animals of simple structure. 

Perhaps the most interesting forms are, however, the 
Coelentera, which often show a double adaptation to 
httoral and to pelagic life. The fronds of the shore 



ANIMAL LIFE IN THE SEA 169 

algae are often covered with the dehcate tracery of 
the sea-firs, colonial coelenterates of sedentary habit. 
Among the branches of the ' fir ' special cups may be 
seen in which buds form. These buds drop out and 
float away, becoming swimming-bells — sexual forms 
which carry eggs and sperms to a distance, so that the 
fertilized egg may find a home far from the parent 
stock. This, which the biologist calls alternation of 
generations, is of common occurrence among the 
coelenterates. We find, however, that frequently one 
of the two modes of life is emphasized at the expense 
of the other. Those delicate bells which we call Cteno- 
phora, or comb-bearers, have no littoral stage at all, 
but are pelagic throughout their life. On the other 
hand, sea-anemones, sea-pens, and their allies, the 
corals of warm seas, and so forth, are littoral, save in 
their earliest stages, and are fixed save in those very 
early stages. No swimming-bell floats away from 
the coral as it does from the sea-fir colony. Between the 
two extremes all stages exist. For example, many of the 
great jellyfish are shore-born, spending a considerable 
part of their lives attached to rocks. Others are pelagic 
throughout, while still others remain permanently 
attached to the rocks, like larvae which have never 
grown up. Somewhat similar conditions occur in the 
tunicates already mentioned (p. 166). 

The sponges, which all require the presence of a sub- 
stratum, are necessarily either littoral or abyssal. 
A great number occur in shallow water, all these being 
attached to some solid body. But there are no very 
obvious adaptations to littoral life, save perhaps that 
shallow-water sponges seem to be always attached, 
while some abyssal forms lie loosely on the surface of 
the ooze. 



170 THE DISTRIBUTION OF 

The protozoa are as well represented on the shore as 
in other parts of the sea, but present no special adapta- 
tions to life here. 

(2) We come next to the pelagic region, where there 
is no substratum, but where many at least of the 
organisms are fully exposed to the action of light. 
With regard to the movements of the water here, we 
must notice first that, in contrast to the littoral area, 
tides are of Kttle importance. On the other hand, 
currents are very important. As is well known, 
the difference in the amount of heat which streams 
down from the sun upon the surface of the sea gives 
rise to differences in temperature and density, which 
cause the surface waters to move in great whirls, the 
ocean currents. As the surface in the different latitudes 
is exposed to different types of winds, and therefore to 
differential evaporation, we have also differences of 
salinity. Roughly speaking, the salinity is greatest in 
warm regions exposed to the drying trades, e.g. in the 
Red Sea and in the Mediterranean, and least towards 
the poles. In not a few parts of the globe we find that 
currents bringing cold water of relatively low salinity 
meet warm currents of highly saline water. When this 
occurs the warmer water floats on the surface of the 
colder, and there is a junction layer where a sudden 
change in temperature, saHnity, and specific gravity 
occurs. Such a meeting of warm and cold currents is 
found, for instance, in the Norwegian Sea, where the 
Polar drift meets the warm currents of that sea ; it 
occurs also off the eastern coast of North America, 
where the Labrador current meets the Gulf Stream ; 
it occurs off the Cape of Good Hope, where the cold 
Benguela current meets the warm Agulhas one, and 
so on. Now, as has been already suggested, such regions 



ANIMAL LIFE IN THE SEA 171 

are regions of great mortality among the pelagic 
organisms, for the stenothermal forms are Idlled by the 
sudden changes of temperature which occur. But there 
is something more than this. The delicate organisms 
which float in the surface waters of the sea are neces- 
sarily very sensitive to changes of density. They must 
be able to float without effort — that is, their specific 
gravity must be that of the water in which they float. 
Very many possess certain powers of adjustment — that 
is, they can vary their specific gravity in harmony with 
variations in the specific gravity of the water. But 
this power of adjustment has its limits. When warm, 
light water is floating on cold, dense water, it is appar- 
ently impossible for the more dehcate forms at least to 
pass through the junction layer of the two, which thus 
forms what Dr. Hjort calls a ' false bottom ', a region 
where living and dead plankton animals accumulate. 
By a series of very ingenious investigations he has shown 
that, in many parts of the ocean, not only does such a 
junction layer between the surface and lower layers of 
water occur, but that this layer is a region of great wealth 
of life. It is a false shore-line in mid-ocean, and Dr. Hjort 
has shown that many of the littoral fish at certain 
seasons leave the shore, and swim out into the open 
ocean, following this line of change of density, where 
food accumulates — where it is as abundant as it is 
near the land. There seems some reason to believe 
that such an accumulation of pelagic organisms in 
an area of sudden change of density occurs in the 
vicinity of aU the great fishing regions of the world, 
and thus, as it were, prolongs the plenty of the shore 
out into the open, and helps to account for the abund- 
ance of fish. 

As to the actual temperature of ocean water, the 



172 THE DISTRIBUTION OF 

statements made above in regard to the temperature 
of littoral waters hold good here also. An important 
point, however, is that nowhere — not even under the 
Equator — does the warmth of the surface layer extend 
far downwards. In practically all parts of the ocean 
the temperature at depths exceeding 1.000 fathoms is 
permanently low, and varies but little throughout 
the year. 

The conditions as to light demand detailed considera- 
tion. Very careful experiments show that all raj's of 
light are present at depths of 50 fathoms. At 300 
fathoms the red and green rays have disappeared, but 
blue and violet rays remain. Some of the violet rays 
are stiU present at 500 fathoms, for photographic plates 
are slightly affected here. At 900 fathoms they remain 
absolutely unaffected after long exposure, and here we 
must suppose that absolute darkness reigns. 

These statements are true for middle latitudes, but 
another point has also to be considered. Obviously, 
the direction of the rays is not the same in all latitudes, 
and therefore they will penetrate to different depths 
in different latitudes. Dr. Hjort gives the following 
figures in regard to the depths at which the same in- 
tensity of light is found in different latitudes : 
In 33° N. lat. at about 430 fathoms depth. 
In 50° N. lat. at about 270 fathoms depth. 
In 67° N. lat. at about 100 fathoms depth. 

This is important, because, as we shall see directl3% 
the intensity of light greatly influences the bathy- 
metrical (i.e. depth) distribution of marine animals. 

The basal food-supply of marine animals — in the 
open as off the shore — consists of algae, so that we 
must add to the above consideration of the conditions 
of life in the open some account of the pelagic algae. 



ANIMAL LIFE IN THE SEA 173 

111 the first place it is noticeable that the larger algae 
are unrepresented in the open sea. The weed which 
floats at the surface of the Sargasso Sea is an apparent 
exception, but it is apparent only, for this weed is torn 
off the shores, especially off the Bahamas, and though 
it proliferates vegetatively in the open, and can live 
there for a time, it is not a truly pelagic form. The 
swarms of animals which live among the floating 
masses of weed in the Sargasso Sea show what an 
important addition to the food-supply of the ocean 
the weed is. 

The basal food-supply of the pelagic animals is, 
therefore, the phytoplankton, the minute algae which 
float at the surface. Necessarily these algae, as light- 
demanding organisms, are limited to the surface layers 
of the water, being especially abundant in the upper- 
most 25 fathoms. They occur, though in diminished 
quantity, down to 50 fathoms. Those found in greater 
depths are resting stages or dead forms. The dead 
forms, as we have already suggested, tend to accumu- 
late, at least temporarily, at levels where a sudden 
increase of density occurs. As regards quantity, the 
water of the open ocean seems to be poorer in algae 
than coastal waters, but, as has been already sug- 
gested, currents may carry the shore forms out to the 
ocean,' and there is reason to believe that then the fish 
of the shore may follow them. 

The next point to be considered is the distribution 
of pelagic animals. There is a tendency among many 
writers, at least tacitly, to confine the term ' pelagic ' to 
those forms which live sufficiently near the surface for 
light to penetrate. There is, however, no real justifica- 
tion for this use. An animal living at a depth of 
2,000 fathoms is as truly pelagic as one living at 



174 THE DISTRIBUTION OF 

a depth of 50 fathoms, if it can be proved that neither 
has any dependence on the proximity of a substratum. 
But here, obviously, a difficulty occurs. A sponge with 
an attaching stalk, taken in deep water, is obviously an 
abyssal form, for it was attached to the bottom. But 
if a net which has been dragged along the bottom at 
a depth of say 2,000 fathoms proves, when examined, 
to contain fish, how can we tell whether these fish were 
truly abyssal forms, or were merely caught as the net 
was hauled up ? The difficulties in coming to a decision 
are great, and until recently there has been a tendency 
to assume that all fish obtained in deep water, and 
having a bizarre form and colouring, large eyes or no 
eyes, and so on, were abyssal fish, feeding on the 
bottom. Dr. Hjort, however, believes that the recent 
(1910) expedition of the Michael Sars, taken in con- 
junction with some previous observations, has yielded 
evidence which proves that many of these curious fish 
are truly pelagic, Hving at or below the light limit. If 
he is right, then pelagic animals may be divided into 
at least three groups : (1) surface forms, most abundant 
in the upper 100 fathoms or so ; (2) mesopelagic or 
intermediate forms, found about the light limit, which 
varies with the latitude ; (3) bathypelagic forms, which 
occur below the limit to which the rays of light pene- 
trate, but yet not upon the sea-floor, of which they 
are independent. 

We must now consider some of the characters of 
pelagic organisms, beginning with the plankton. Plank- 
ton animals are those able to float in water udthout 
exertion, and have usually flattened and expanded 
bodies. Sometimes, as in the very abundant copepods, 
a globule of oil makes the body hght. At other times, 
as in some protozoa, and such forms as the sunfish, 



ANIMAL LIFE IN THE SEA 175 

the lightness is due to the presence of air or another 
gas. In the surface forms the body is often transparent 
and colourless, so that it is invisible as it floats in the 
clear water, while in other cases it is blue or violet, so 
that it will equally be invisible when seen from below 
against the sky. That these peculiarities are adaptive 
is suggested by the way in which they appear in un- 
related forms. Thus while the shore annelids are 
brightly coloured, Tomopteris, a pelagic form, is colour- 
less, and has an expanded body. The same peculiari- 
ties appear in Sagitta, a worm of uncertain affinities ; 
in Phyllirhoe, a curiously modified and shell-less 
gasteropod ; in Salpa, a pelagic tunicate, and so on. 
The surface jellyfish are blue or violet or almost colour- 
less, while in deep water bright-red forms occur. Many 
of the pelagic forms of the surface are phosphorescent. 
We see this in the protozoon called Noctiluca, in the 
beautiful tunicate called Pyrosoma, in some pelagic 
Crustacea, and so forth. Surface pelagic forms are so 
numerous that no useful purpose would be served by 
giving a list, but it may be interesting to note those 
groups which have no pelagic representatives. While, 
as already suggested, very many types of Coelentera are 
pelagic, there are no pelagic alcyonarians (sea-pens, 
&c.), and there are no pelagic sponges. With one 
exception, to be considered later, there are no pelagic 
echinoderms, though their larvae are often pelagic. 
There are no pelagic bivalve molluscs, though many 
different kinds of gasteropods are adapted to life in 
the open sea, the sea-butterflies (Pteropods) being good 
examples. Some other less familiar groups are also 
unrepresented in the open sea. 

On the other hand, there are enormous numbers of 
pelagic larvae. As young animals have often delicate 



176 THE DISTRIBUTION OF 

translucent bodies it would seem as though they could 
be very readily adapted to the pelagic life. As two 
interesting forms mention may be made of the trans- 
parent larva of the eel, called Leptocephalus, because 
its relation to the parent was for long unknown, and the 
glass crab (Phyllosoma), which is the larva of the rock 
lobster, but was similarly for long regarded as an 
independent organism. 

Very remarkable is the presence in the open sea of 
the members of an insect genus, Halobates, a kind of 
bug, related to the forms which skim over the surface 
of fresh-water ponds. Some fifteen species of Halobates 
are known from the warmer parts of the oceans. The 
insects appear to be perfectly pelagic in that even the 
eggs are produced in the open, but they may also 
approach shores, for what reason is not known. The 
female carries the eggs for a time attached to her own 
body, and the young have been found on floating soHd 
bodies in the sea. Wings are completely absent, and 
the body is covered with a greyish pubescence, which 
shines in the sunlight. The animals breathe air, and 
belong rather to the surface of the ocean than to its 
waters. 

In contrast with these plankton or drifting forms, 
we have in the open sea a number of powerful swimmers 
(nekton) able to make headway against the currents. 
The most important of these are the whales and their 
allies, whose distribution is tied to that of the animals 
upon which they prey. Thus the huge cachalot or sperm 
whale {Physeter macrocephalus) is found especially in 
warm seas, where it finds the large cuttles upon which it 
feeds. The related bottle-nose (Hyperoodon), which also 
lives on cuttles, occurs in colder seas, and is found 
especially in the North Atlantic. The whalebone whales 



ANIMAL LIFE IN THE SEA 177 

(Balaena, &c.) feed on the floating plankton, especially 
on sea-butterflies (Pteropods), and are very common 
in cool and cold waters, though widely distributed. On 
the other hand, the fish-eating dolphins and porpoises 
especially frequent shallow waters, where the fish on 
which they prey are most frequent. 

With the exceptions already given, purely pelagic 
fish are not very abundant, at least in the surface 
waters. The reason is apparently that food near the 
surface is not sufficiently abundant. Professor Bouvier 
notes that the Princesse Alice, the Prince of Monaco's 
yacht, while cruising in mid- Atlantic, found practically 
no surface fish, except when some floating wreckage, 
with a burden of attached invertebrates, such as 
Crustacea, &c., drew them to the surface. Among the 
surface forms may be noted the flying-fish (Exocoetus), 
the beautiful ' dolphin ' (Coryphaena), and its allies, 
the bonito {Thynnus pelamys), another flying form, 
related to the mackerel, which is also pelagic. All these 
forms, however, despite their obvious adaptations to 
pelagic life, are more abundant as the land is approached 
than far away from land. 

The above forms may be regarded as characteristic 
of the upper 100 fathoms or so of water. We have next 
to consider the mesoplankton and mesonekton — that is, 
the forms which occur between the surface layers of 
water and the bottom, near the light limit. The study 
of these is necessarily a difficult matter, involving 
the use of comphcated methods not hitherto used at 
very great depths. Provisionally, however, the follow- 
ing statements may be made, these being based especi- 
ally on the results obtained by the Michael Sars 
expedition. 

At depths between 200 to 300 fathoms, but varying 

1404 M 



178 THE DISTRIBUTION OF 

with the latitude for the reasons aheady discussed, 
there seems to be a fauna of silvery or iridescent 
animals, of which the fish have been chiefly investi- 
gated, though medusae, and doubtless other forms also 
occur. The fish hving at these depths inhabit an 
environment where a considerable amount of sunhght 
penetrates, especially blue and violet rays. They have 
often large eyes, which sometimes protrude at the end 
of short stalks, and are then called telescopic. Large 
light organs are present, which perhaps catch the last 
rays of sunhght. An example is the silvery fish Argyro- 
pelecus affinis, which fives in the Atlantic at depths of 
somewhere about 200 fathoms ; at night, when the 
fight conditions are the same near the surface as in the 
depths where it habitually dweUs, this fish has been 
found within some 80 fathoms of the surface. Its 
young have the same colouring as their parents, and 
live in the same depths. Another form with the same 
colouring and characters is Cydothone signata, which 
lives at a depth of about 300 fathoms. 

Still deeper, at depths of from 300 to 500 fathoms, 
where aU trace of red and green rays have completely 
disappeared, occur forms in which the colouring is 
black or red. In the absence of any red rays both 
these colours must look the same, and either will pro- 
tect the animal. At these depths occur deep -red or 
chocolate-coloured medusae, the only pelagic echino- 
derm (Pelagothuria), bright -red prawns, such as 
Acanthephyra muUispina, and red or black fish, Se- 
hastes norvegicus being an example of the former and 
Goniostoma elongatum of the latter. The last-named 
fish is purpfish-black, with small fight organs and 
small eyes. It has huge jaws, a common feature in 
these deep-water fish. A very curious point about it 



ANIMAL LIFE IN THE SEA 179 

is that in the daytime it lives at about 300 fathoms, 
but at night it rises to within 80 fathoms of the surface. 
Its young are crystal clear, and are surface forms living 
in the upper 80 fathoms. On the other hand, some 
members of the genus Alepoeephalus live as far down 
as 1,100 fathoms, and have no light organs. Their 
young are the same black colour as the parents, and 
live also in the great depths. 

To sum up, so far as we know at present, forms 
which live in the surface waters of the ocean are crystal 
clear or pale violet or blue. Those which live in layers 
where only blue and violet rays penetrate freely tend 
to be silvery and to have large eyes and large light 
organs. Still deeper, where no red and no green rays, 
even in some instances no rays at all, penetrate, the 
colour becomes red or black, and light organs are small 
or disappear. That there is an intimate relation between 
the characters and colouring of the organism and the 
amount of light present is shown by the fact that when 
the larva inhabits the same depth as the parent it has 
the same colours. When it inhabits another zone it 
takes on the normal colouring of the inhabitants of 
that zone. Further, the fact that the forms from 
deeper water occur in different layers of water in 
difEerent latitudes — the level corresponding to the 
degree of penetration of light in the particular latitude, 
so that the animals live higher up in high latitudes 
than in low — suggests that the life of the animals is 
strongly influenced by the amount of light present. 

One other point is interesting in regard to the life 
of these depths. Just as the littoral fishes often send 
pelagic larvae out to the open sea, so some of the 
abyssal fishes seem to have bathypelagic larvae, i.e. 
larvae living in the open water, but at considerable 

M 2 



180 THE DISTRIBUTION OF 

depths. Thus the members of the genus Macrurus, 
believed to be true abyssal, that is ground-liAnng, forms, 
have apparently such eggs and larvae. The abyssal 
hermit crabs, also, have bathypelagic larvae, just as 
the Uttoral forms have larvae which form part of the 
surface plankton. 

(3) The abyssal region of the oceans is contrasted 
with both the other regions in that its waters must 
be permanently calm. It is in harmony with this 
calm that we find, as already stated, some deep-sea 
sponges which have no attachment to the substratum, 
upon which they seem to lie loosely. The pressure 
must be enormous, for the animals of the depths sup- 
port a weight of several miles of sea-water upon their 
bodies. Though there are no plants, oxygen seems to 
be abundant. But this is a consequence of the well- 
developed circulation of the great oceans, and is not 
a feature of enclosed seas. Thus the Black Sea has no 
animals in its depths, and the waters there are impreg- 
nated with sulphuretted hydrogen, and contain but 
little oxygen. In the Mediterranean the conditions are 
less extreme, but the deep-sea fauna is scanty. Light 
is, of course, entirely absent in the depths. The water 
is permanently cold. The basal food-supply must 
consist of the dead animals of the upper zone, which 
fall downwards through the water as they die. In 
consequence we find that many of the abyssal forms 
are mud-eaters. To what extent the floor of the 
ocean is peopled still remains a difiicult question. 
As aheady noted, Dr. Hjort beheves that genuine 
abyssal fish, in the sense of grovmd forms, are few, 
most of the so-caUed abyssal forms being bathypelagic 
and having been obtained in the process of hauling 
in the dredge. But there can be no doubt that many 



ANIMAL LIFE IN THE SEA 181 

invertebrates do occur on the sea-floor in the greatest 
depths, especially over regions covered by Globigerina 
ooze. Among these invertebrates sponges and echino- 
derms preponderate, molluscs and crabs among Crus- 
tacea being rare. Of the sponges the old-fashioned 
siliceous forms are numerous, and calcareous sponges 
are absent. A few corals occur. Among the echino- 
derms all the classes are represented, and the old- 
fashioned crinoids, rare in shallow water, are relatively 
abundant. Among the sea-urchins the special feature 
is the abundance of old-fashioned irregular forms, which 
occur so abundantly as fossils. Annehds occur especi- 
ally in the red clay. In harmony with the great 
uniformity of the conditions over wide areas, the 
abyssal animals are widely distributed. Further, as 
the conditions of temperature, and during the long 
Arctic night the conditions regarding illumination, 
show resemblance in polar and abyssal regions, there is 
apparently some resemblance between polar animals 
and abyssal animals. 

References. The forty-two volumes of the ' Challenger' Reports ( 1880- 
91) give the results of the epoch-making cruise of that vessel. More 
popular accounts of its work are to be found in Mosely, Notes by a Natural- 
ist on the ' Challenger ' (London, 2nd ed., 1892), and Wyville Thomson, 
The Depths of the Sea (London, 1873), and Narrative of the Voyage of the 
''Challenger'' (London, 1885). The following may also be consulted: 
Ortmann, Grundzuge der marinen Tiergeographie (Jena, 1896) ; Chun, 
Aus den Tiefen des Weltmeeres (Jena, 1900) ; Marshall, Die Tiefsee und 
ihr Leben. For the more recent work discussed in the present chapter, 
see Hjort, The ' Michael Sars ' North Atlantic Deep-sea Expedition {Geo- 
graphical Journal, April and May, 1911); Hjort, Die erste Nordmeer- 
fahrt des norwegischen Fischdampfers ' Michael Sars ' im Jahre 1900 
(Petennann's Mitteilungen, IV, 1901), and The Deptlis of the Ocean, by 
Sir John Murray and Dr. Johann Hjort (London, 1912). Two interesting 
popular articles on the work of the Princesse Alice are Les Vertibris de 
la Surface and Im Faune Pilagique des Invertebres, by Professor Bouvier 
{Revue Ginirale des Sciences, 1906). 



CHAPTER IX 

THE ANIMALS OF LAKES AND RIVERS 

The water of rivers and of very many lakes differs 
from that of the sea in the absence of any considerable 
quantity of common salt, making it ' fresh ' instead 
of salt. Such bodies of water contain a special fauna, 
which, as contrasted with the fauna of the ocean, may 
be described as impoverished ; but in addition to this 
negative character, this fauna possesses also some 
positive ones, which we shall consider later. Certain 
other lakes, either because they had a former connexion 
with the sea, or because they have no outlet, contain 
saline water. Such masses of water maj^ contain some 
animals with distinctly marine affinities, e. g. in the 
Caspian are found a seal and a kind of herring. But 
the Caspian is far from being as salt as the sea, and in 
addition to animals of marine type it contains some 
typically fresh- water fishes. On the other hand, masses 
of very salt water, such as the Great Salt Lake of Utah, 
contain pecuhar brine-shrimps (Artemia) not found 
in the sea. A still further compUcation is introduced 
by the fact that certain lakes, though their waters are 
perfectly fresh, contain animals of distinctly ' marine ' 
facies. Thus Lake Baikal, though its waters are not 
salt, lodges a seal aUied to the Caspian seal, and a 
marine worm ; Lake Tanganyika, in Central Africa, 
contains several animals of marine type, and so on. 
In consequence we cannot sharply separate fresh- 
water animals from marine ones, in the sense of imply- 



THE ANIMALS OF LAKES AND RIVERS 183 

ing that all the latter live only in the ocean, and that 
lakes and rivers contain only the former ; nor can we 
assume that all aquatic animals can be divided into 
marine and fresh-water types, for this would exclude 
forms like the brine-shrimps, characteristic of salt 
lakes and brine pools. But, at the same time, it is 
convenient to recognize a general distinction between 
the animals of the oceans, the marine forms, and those 
characteristic of lakes and rivers, which are for the 
most part fresh- water animals. 

Using the terms in this general sense, we may note 
that the poverty of the fresh-water fauna is due to the 
relatively unfavourable conditions. Among these un- 
favourable conditions we probably need not include 
the absence of considerable amounts of salt dissolved 
in the water, for the presence of an appreciable amount 
of salt, e.g. in the Caspian, does not give rise to a 
marked increase in the fauna as compared with fresh- 
water lakes, and the presence of a large amount of 
salt, e.g. in the Great Salt Lake, is distinctly inimical 
to animal life. 

Before proceeding to discuss the especially unfavour- 
able conditions, we may note that it is generally 
believed that life originated in the sea, not in fresh 
water, and that therefore all the animals now found 
in rivers and lakes must have originated in one of two 
ways : (1) they may have been derived directly from 
marine forms, or (2) they may have been derived from 
land animals which have reacquired the aquatic habit 
of their remote ancestors. 

Of the first group, fresh-water fishes may be taken 
as examples. They have certainly had marine ances- 
tors, and in some cases, e.g. the eel and the salmon, 
the existing forms have retained the power of living in 



184 THE ANIMALS OF LAKES AND RIVERS 

the sea as weU as in fresh water. Similarly, the bivalve 
molluscs of the lakes and streams have certainly had 
marine ancestors. Most of the higher Crustacea hve in 
the sea, and the few crayfish and prawns which live 
in fresh water are certainly descended from ancestors 
which Uved in the open ocean. 

It is otherwise with most of those numerous forms 
which, though they live in water, are yet adapted for 
breathing air. The otter which haunts the salmon 
rivers has lungs no less than its distant relative the 
polecat ; the water-tortoises have lungs Hke the land 
forms ; the water-beetles and the many insect larvae 
found in pools, the water-spider, the water-mites, the 
pond-snails, are all air-breathers, and their peculiar 
respiratory organs would be inexplicable if we could 
not assume that their immediate ancestors Hved on 
land. In these cases there is no reason to beheve that 
the animals have ever sought the sea since the time 
when their far-off ancestors acquired terrestrial charac- 
ters. Therefore in possessing some of these forms 
the fresh-water fauna is not poorer but richer than 
the sea, which has hardly any insects (cf. p. 176), no 
air-breathing moUuscs, no true spiders, and so on. 
Again, while most amphibians have a fresh-water 
larval stage, and some pass much of their life in water, 
no hving amphibian is ever found at any period of its 
life in the sea. 

But when we come to consider the groups which are 
richly represented in the sea, the tale is different. The 
echinoderms are exclusively marine — no starfish, sea- 
urchin, brittle-star, nor sea-lily is known from fresh 
water. No cuttle hunts its prey in the depths of the 
great lakes, nor creeps along river bottoms. The poly- 
chaete worms are almost exclusively marine, and the 



THE ANIMALS OF LAKES AND RIVERS 185 

higher Crustacea largely so. The great group of the 
Coelentera is very scantily represented in fresh water, 
where also there are but few sponges. Fresh- water fish 
also are few in number as compared with their marine 
allies, though they include some peculiar forms, like 
the ganoids (e.g. sturgeon, bony pike, &c.), and the 
dipnoi or double-breathers. It is, however, interesting 
to note that of these pecuUar fish all the three living 
dipnoi, and at least one ganoid (Polyp terus) have 
accessory breathing organs which enable them to breathe 
air, as well as gills. This fact, taken in conjunction 
with the relatively large numbers of air-breathing 
invertebrates, suggests that one difficulty in colonizing 
fresh water has always been its relative deficiency in 
oxygen. In the general case this applies, of course, to 
lakes and inland seas rather than to rivers, whose 
water is oxygenated by its motion. But where a 
marked dry season occurs, as in many parts of the 
globe, the rivers may periodically cease to flow, and 
be represented by a series of stagnant pools, whose 
waters become very fetid — conditions highly unfavour- 
able to animal life. 

In the lakes of temperate regions, where the surface- 
water periodically cools below the point of maximum 
density of water, a vertical circulation is produced which 
carries down oxygen to the deeper layers of the water, 
at least at certain seasons. This makes Ufe in the 
deeper layers possible, though some American experi- 
ments suggest that the oxygenation of these deeper 
layers occurs only in spring and autumn, as the ice 
melts in the former case, and before it is formed in 
the latter. In the summer the heating of the surface- 
water gives rise to a stratification into two layers, 
when the warm oxygenated surface-water lies upon a 



186 THE ANIMALS OF LAKES AND RIVERS 

deeper, colder layer, whose oxygen is only renewed 
very slowly. This relative paucity of oxygen naturally 
checks life in the deeper parts of the lake. 

In tropical lakes the fact that the surface-water does 
not cool in the same way in autumn, and that there is 
no spring melting of ice, makes the vertical circulation 
much less marked, and leads to a virtual absence of 
a deep-water fauna. In brief, then, the deep-water 
fauna of lakes is always poor, because of the absence 
of a well-marked circulation of the water, and the defi- 
ciency in the amount of oxygen, with the resultant 
paucity of life, increases towards the Equator. 

The second unfavourable condition in fresh water is 
its frequent turbidity. Rivers are powerful eroding 
and transporting agents, lakes are great filter-beds on 
the course of rivers ; necessarily, therefore, the waters 
of both must often contain fine particles in suspension, 
which would form a deposit on the surface of the 
breathing organs of animals Hving in them, and greatly 
retard respiration. The importance of this may be 
illustrated by an example. The Firth of Forth is 
a great estuary swept by the tides, once inhabited by 
great numbers of marine animals tolerant of estuarine 
conditions, notably by oysters. There is much evidence 
to show that its waters are becoming muddier year by 
year, apparently because drainage of the ' mosses ' in 
the upper regions of the river has made the run-off 
there more rapid. As a result of the increasing muddi- 
ness many animals have disappeared — the oyster-beds 
long ago ceased to be productive, and other forms also 
are diminishing. Now if an increase in the amount of 
mud in the water kills estuarine animals, which are 
naturally tolerant of some suspended matter, even 
a small amount of suspended matter will prevent the 



THE ANIMALS OF LAKES AND RIVERS 187 

growth of the more dehcate animals, and must be 
a great bar to the passage of marine animals up estu- 
aries and rivers. Almost any coast-Une will illustrate 
the same thing on a smaller scale. The shore collector 
knows that to get the rarer and more deUcate animals 
he must seek rocks or beaches remote from the mouths 
of streams, for at the immediate outlets of these only 
the hardiest forms occur. This statement is not in- 
consistent with that already made, that the waste of 
the land is an important part of the food of the sea- 
animals, for oxygen is a prime necessity which precedes 
even the need of food, and few animals can take in 
oxygen if their respiratory organs are choked with mud. 

But it is not only the suspended matter in the water 
of lakes and rivers which is inimical to animal hfe. 
The presence of large amounts of hme or manganese 
salts, or of humic acid, may render the water unsuitable 
to certain forms. 

Still another point of great importance is the enor- 
mous variation in temperature to which lakes and 
rivers are subject. These variations are normally so 
great that they render the water absolutely unsuited 
to stenothermal animals. All fresh- water forms must 
be eurythermal (cf. p. 160), and temperate and polar 
forms must have special means of protecting them- 
selves, or their offspring, against the cold of winter. 
In the ' lakes ' of Victoria Land, which are almost per- 
manently frozen, the naturahsts of Sir Ernest Shackle - 
ton's expedition found rotifers which can apparently 
tolerate being frozen into the ice for years, and will 
yet hatch out if the temperature rises and the ice melts. 
This is an extreme case, but it suggests the adaptations 
necessary before animals can thrive in small masses of 
water. Low temperatures are not, however, the only 



188 THE ANIMALS OF LAKES AND RIVERS 

danger. High temperatures, with resultant desicca- 
tion, are just as dangerous, and must also be provided 
against. The amoebae in a waterspout can be dried to 
dust, and will lie unharmed within their protective 
cysts until the rain comes, and the spout once again 
becomes suitable for their active life. In the swamps 
of the Paraguay or of the Central African rivers, the 
lung-fishes He in their mud cases, waiting till the wet 
season again permits them to become active. Drought 
and freezing, high temperatures and low, are risks 
which every fresh-water organism must face, and the 
lessons learnt in the conflict with them are stamped 
deep on all the inhabitants of stream and lake. In 
these, as on dry land, life in the temperate and frigid 
zones is markedly seasonal, and it is interesting to note 
that where the problem of seasonal adaptation cannot 
be directly faced, it may be avoided. For example, 
those shallow bodies of water which are favoured by 
frogs as spawning-places are very apt to dry up in full 
summer, but the tadpole avoids the risk of drought 
by adjusting its time of metamorphosis to the time of 
drought, so that it is ready to leave the water at the 
time when the pond would naturally dry up. Every 
summer one may find cases where the adjustment has 
not been sufficiently delicate, so that thousands of tad- 
poles die because the drought comes before they are 
ready for their land life. In autumn the ponds fill again, 
and the Httle frogs return again to them to pass the 
winter in their mud. 

One other unfavourable feature of rivers and lakes 
is found in the strength of their currents. The waters 
of the ocean are swayed also by currents, but within 
considerable limits, and with the exceptions already 
given (p. 161), such currents cause Httle harm to 



THE ANIMALS OF LAKES AND RIVERS 189 

marine animals. Tides and currents sweep the members 
of the plankton hither and thither, but the regions 
into which they are swept may be more suitable than 
those they have left — in the case of the littoral animals 
the currents are the great distributors. But for a lake 
or river animal to be swept out to sea must in the 
general case mean death, for it means the passage from 
a speciaUzed environment to which the animal has 
become adapted through progressive variation, to 
another to which it has no adaptations. 

In the nature of things littoral animals must have 
always had special faciUties — that is, facilities in regard 
to space — ^for conquering fresh water. So far as their 
relations in space go, it is relatively easy for them to 
progress, actively or passively, from the shore up 
rivers and estuaries. But we have already seen that 
it is one of the great peculiarities of Httoral animals 
that they tend to produce free-swimming young, or 
free-swimming stages, whose purpose it is to ensure 
distribution along the shore, and the existence of these 
free-swimming stages or young offers a serious obstacle 
to the colonization of fresh water. For example, in 
some artificial ponds at the mouth of the Ganges 
a very curious fauna has been described {Records Indian 
Museum, i. (1907) p. 35). These ponds are sometimes 
connected with the sea, and sometimes shut off from 
it, and are sometimes filled with water rendered very 
salt by evaporation, while at the rainy season the water 
is nearly fresh. In spite of these variations in salinity, 
a number of marine forms occur, including a sea- 
anemone, a kind of sea-fir (Hydromedusan), and a 
polychaete worm, showing that it is not its freshness 
alone which prevents such forms from colonizing fresh 
water. Now sea-anemones produce usually free- 



190 THE ANIMALS OF LAKES AND RIVERS 

swimming larvae called planulae ; Hydromedusae 
produce free-swimming medusoids ; polychaete worms 
have free-swimming larvae called trochospheres, all 
delicate forms incapable of swimming against currents. 
These particular ponds have at intervals a connexion 
with the sea, and so can be peopled afresh from it, but 
if we suppose that at some future period the connexion 
with the sea were to be reduced to a swift-flowing 
stream, could we suppose that the animals would 
persist ? Obviously not, for the medusoids, the 
planulae and the trochospheres would tend to be swept 
out to sea by the stream, and there would be thus no 
young forms to replace the parents when death took 
place. So real is this danger that, with rare excep- 
tions, fresh-water organisms have no free-swimming 
stage in their hfe-history. Only those marine animals 
could colonize fresh water which had no plankton 
stage in their Hfe-history, or which managed somehow 
to survive until this free-Uving stage could be sup- 
pressed by progressive variation. This perhaps gives 
us a second reason why so many animals with a 
terrestrial ancestry have succeeded in colonizing fresh 
water, for these forms would not have a free-swimming 
stage. Thus while most marine gasteropods have free- 
swimming larvae, fresh-water snails, Uke land snails, 
hatch as miniature adults, which makes Hfe in ponds 
and streams easy for them. These arguments of course 
only apply to those deUcate organisms which are in- 
capable of swimming against currents. Relatively 
powerful swimmers, like many insect larvae, can 
resist moderate currents, though they avoid regions 
where the water is in rapid movement. 

But, it may be said, in a large lake the need for dis- 
tribution is as great as in the sea, how do the lake 



THE ANIMALS OF LAKES AND RIVERS 191 

animals succeed in spreading from one part of the lake 
to another if they have no free-swimming stage ? The 
answer is apparently that the distribution is largely 
passive, being assisted by sudden freshets, which may 
produce currents of unusual violence, capable of carry- 
ing adults, or, more likely, resting eggs to a distance. 
In addition there are some curious special adaptations. 
We may take two examples of familiar forms. The 
fresh-water hydra as contrasted with the marine sea- 
firs has no free-swimming stage. While the weather is 
warm it reproduces itself by buds ; towards autumn 
it produces coated eggs which survive the winter, and 
produce fresh hydrae in spring. These shelled eggs 
are doubtless easily transported by currents. More 
remarkable are the conditions in the fresh-water 
mussel (Anodon). Here the mother retains the young 
within her body till sticklebacks approach the mud in 
which she is living. She then discharges the young, 
who fix themselves to the fish, and are thus carried 
about for a time, and so distributed. Later they drop 
from the stickleback to the mud, and develop into 
mussels like the parent. 

With this preliminary account of the conditions of 
Hfe in lakes and rivers, and of the resultant adapta- 
tions, we may proceed to consider the animals which 
constitute the fauna. 

A considerable number of mammals show at least 
a partial adaptation to fresh -water life. Thus we have 
many kinds of otters, which have webbed feet and feed 
upon fish ; not a few insectivores, such as the common 
water-shrew and the Russian desman ; various rodents, 
such as the beaver and the water-vole ; a monotreme, 
the curious duck-mole or Ornithorhynchus of AustraHa, 
and so on. In most of these cases the modifications are 



192 THE ANIMALS OF LAKES AND RIVERS 

not very profound, not sufficient to cause the animals 
to diverge very markedly from their terrestrial alhes. 
This suggests that in most cases the modification is 
relatively recent. Among the more frequent modifica- 
tions are webbed feet, used in swimming, close dense 
fur which prevents the water reaching the skin and so 
chilhng it, and a broad flattened tail used as a rudder. 
Of mammals with more profound adaptations to 
aquatic life, few occur in inland waters. We have 
already spoken of the Lake Baikal seal {Phoca sibirica) 
and the Caspian seal {Phoca caspica), both closely 
related to the Ringed seal of northern waters. The 
Baikal seal also occurs in Lake Oron, on the course of 
the river Vitim, and in addition to its seal Lake Baikal 
shows certain ' marine ' features in its molluscan fauna. 
The explanation is perhaps that the lake had once 
a connexion, direct or indirect, with the great inland 
sea of Tertiary times. Among the Sirenia the manatee 
is largely fresh-water, ascending such rivers as the 
Amazon almost to their sources. But these animals 
thrive equally well in the ocean, and their presence in 
large rivers requires no special explanation. 

The large Cetaceans are exclusively marine, but 
certain dolphins occur in fresh water. The one which 
is most definitely adapted for this habitat is the blind 
dolphin of the Ganges, Brahmaputra, and Indus 
{Platanista gangetica). This animal occurs from tidal 
waters to the upper reaches of the rivers, as high up 
as the depth of the water permits, but it has never 
been seen in the sea. These dolphins feed upon fresh- 
water fish and river prawns, and are apparently primi- 
tive forms which, like Ganoid fish, have found a refuge 
in fresh water. Other fresh-water dolphins occur in the 
large rivers of South America, especially the Amazon. 



THE ANIMALS OF LAKES AND RIVERS 193 

A very large number of birds haunt the vicinity of 
fresh water, being attracted to it, especially at certain 
seasons, by the relative abundance of food there. 
Such forms, however, live on the surface rather than 
in the water. 

In regard to reptiles it is interesting to note that 
among the Chelonia, as among mammals, the adapta- 
tions to the aquatic life are much more marked in 
marine than in fresh-water forms. Marine turtles have 
their limbs turned into paddles ; fresh -water Chelonians 
swim by limbs which are only slightly modified as com- 
pared with terrestrial forms. This is quite parallel to 
the conditions which occur in mammals. Such typically 
marine mammals as seals, Cetaceans, and Sirenians 
have their limbs (when present) turned into paddles. 
Such fresh-water carnivores as otters, fresh-water 
rodents like water-voles and beavers, fresh-water in- 
sectivores hke water-shrews, have only slightly modified 
limbs, retaining many features found in terrestrial 
types. This is equivalent to saying that for an air- 
breathing animal the modifications which fit an animal 
for life in the sea must necessarily be more profound 
than those which fit it for life in fresh water, which 
usually occurs in relatively small masses, and where 
the animal inhabitants often retain considerable depen- 
dence upon the land. 

Among the Chelonia a considerable number spend 
at least a great part of their time in the water. As 
two examples we may take the American Snapping 
Turtle {Chelydra serpentina), a form reaching a con- 
siderable size, which is found in lakes, ponds, and rivers 
throughout the greater part of North America. It has 
strongly webbed feet and is carnivorous. As might be 
deduced from its limbs, which are but little modified, 

1404 If 



194 THE ANIMALS OF LAKES AND RIVERS 

it leaves the water, should want of food or any 
other cause render this necessary, and is capable of 
(awkward) progression on land, in a way that would 
be impossible for a marine turtle. In Central and 
Southern Europe the ponds and swamps are inhabited 
by the pretty little pond tortoise {Emys enropea), which 
has also webbed feet. These little creatures are fond 
of coming out of the water to bask, and migrate from 
one pond to another if the first shows signs of drying up. 

The same tale of partial adaptation to aquatic life 
can be told of the various kinds of crocodiles, which, 
like the forms just mentioned, seem to seek the water 
for the sake of the food to be obtained there. The 
living crocodiles are still so far bound to the land that 
they leave the water voluntarily, either to bask in the 
sun, or in order to migrate from one region to another, 
or to lay their eggs. 

None of the snakes show such definite adaptations 
to life in fresh water as do the sea-snakes to life in the 
sea, but certain forms enter the water freely in search 
of food. This is especially true of the common grass- 
snake {Tropidonotus natrix), which sometimes spends 
the greater part of its life in water, in which it swims 
easily. 

The amphibians show some very curious conditions 
in connexion with adaptations to the aquatic life. The 
normal condition, as already suggested, is that the 
young live in the water and breathe by gills, while the 
adults live on land and breathe by lungs. But there 
are some interesting exceptions. Throughout much of 
North America, and especially in Mexico, there occurs 
a salamander {Amhlystoma tigrinum), which when adult 
is normally terrestrial, except at the breeding-season, 
and is of a brownish colour, with yellow spots and 



THE ANIMALS OF LAKES AND RIVERS 195 

blotches. The larvae, known as axolotls, have large 
external gills, slender limbs, and a tail fringed with 
a swimming membrane. Now, at times, under natural 
conditions, but for causes not clearly understood, these 
larvae may become sexually mature and lay eggs, while 
remaining in the water, and while retaining larval 
characters. That is, of the Amblystoma eggs laid in 
a lake some may give rise to the salamander-like adult, 
while others may breed while retaining tadpole charac- 
ters. As a much rarer phenomenon this may occur 
in the common newts, which sometimes breed while 
retaining the characters of the tadpole. 

In a more advanced form the same condition occurs 
in certain other amphibia, which, as it were, never grow 
up, but remain permanently in the tadpole stage. In 
the lakes and swamps of the eastern part of the Missis- 
sippi basin, and in some of the Canadian lakes, there 
occurs an amphibian of about one foot in length, with 
three pairs of external gills and a fringed tail, called 
Necturus maculatus. This animal uses both its lungs 
and its gills for breathing purposes, and retains its gills 
throughout life. The same statements may be made of 
Siren lacertina, the mud-eel of parts of the United 
States. These are examples of the reacquisition 
of the exclusively aquatic habit by animals whose 
ancestors had become adapted for life both on land and 
in water. Amphibians, it may be noted, have probably 
been derived from fishes of the ' ganoid ' type — that is, 
originated from fresh-water forms (see p. 202). 

This brief account of the air-breathing vertebrates 
found in lakes and rivers enables us to draw some 
general conclusions in regard to these. Obviously we 
can classify them under three headings : (I) The 
amphibians, which possess gills at some stage in their 

N 2 



196 THE ANIMALS OF LAKES AND RIVERS 

life-history as well as lungs, illustrate the transition 
from the fresh-water to the terrestrial life, some forms 
showing a tendency to revert to the aquatic life ; 
(2) such forms as otter and desman among mammals, 
water-tortoise and crocodile among reptiles, show land 
animals in the process of reacquiring aquatic charac- 
ters, either because food is easier to get in water than 
on land, or because life is safer there for relatively 
helpless animals ; (3) the fresh- water dolphin of the 
Ganges, the manatee, &c., exemplify the acquisition 
of the fresh- water habit by animals adapted to life in 
the sea, but driven from the sea by the competition of 
more advanced forms, or quitting it voluntarily in 
search of food. The seals found in Lake Baikal and the 
Caspian Sea are truly marine forms, more or less 
accidentally cut off from their natural habitat. 

The remaining animals of lakes and rivers, includ- 
ing fishes and invertebrates, are of more ancient origin, 
and have had more time to become fundamentally 
modified. The manatee is still a marine animal, the 
fresh-water dolphin of the Ganges became fluviatile at 
a period which is geologically but of yesterday, but the 
fresh- water hydra, the fresh- water crayfish, the fresh- 
water mussels have had time to become greatly modified. 

The fauna of swift rivers must in the general case 
consist only of powerful swimmers like fish and fresh- 
water crayfish, or of animals which can so fix them- 
selves as to avoid the force of the currents. In lakes 
and ponds, on the other hand, there is a greater wealth 
of life, and it is possible, as in the sea, to divide this 
life into littoral, pelagic, and abyssal groups. But of 
these groups the littoral is by far the largest, because 
it is enriched by many forms, like the larvae of insects, 
which retain some dependence upon the land. The 



THE ANIMALS OF LAKES AND RIVERS 197 

abyssal fauna is sometimes virtually absent, e.g. in the 
Caspian, owing to the paucity of oxygen, and its members 
rarely if ever show the specialization seen in the 
animals of the ocean abysses. This seems to be partly 
because lakes are necessarily temporary phenomena, 
destined to be filled up after a longer or shorter period, 
and therefore there is no time for a special abyssal 
fauna to develop. As considerable differences exist in 
the fauna of different lakes, it seems better to give 
some account of a few types rather than to make 
general statements in regard to lakes as a whole. 

The fauna of the lochs of Scotland has been studied 
in great detail by the members of the Scottish Loch 
Survey, so that it is possible to make a considerable 
number of general statements in regard to it. 

The members of the Survey studied in all 562 lochs, 
and, exclusive of vertebrates and of insects and their 
larvae, 440 species of animals were found. Most of the 
lochs studied are shallow, but Loch Morar has a maxi- 
mum depth of over 1,000 feet, and Loch Ness of over 
750 feet, rendering an abyssal fauna possible. The 
members of the Survey did not especially investigate 
the fishes. We know, however, from other sources 
that the special feature is the number of members of 
the salmon family, which run into many species or 
varieties ; cf . the Loch Leven trout, which is peculiar 
to that lake. 

Of the invertebrates the majority may be described 
as littoral in that they occur in shallow water, near 
the margins of the lochs. Here are found many insect 
larvae, and not a few adult insects adapted for life in 
the water, e. g. water-beetles and water-boatmen. Here, 
too, are found nearly all the few molluscs, including the 
large mussels and the small fresh-water snails. Small 



198 THE ANIMALS OF LAKES AND RIVERS 

Crustacea are numerous, especially those forms popu- 
larly called water-fleas, from their jumping movements. 
Many rotifers occur, together with such small animals 
as water-mites, water-bears (Tardigrada), and so forth. 

Only some thirty species are typically pelagic and 
thus constitute the plankton. These comprise fourteen 
small Crustacea, twelve rotifers, and four protozoa. 
Of these thirty species most are very wddely distributed, 
the animals which constitute the fresh-water plankton 
being all but cosmopolitan, and believed to form ' the 
oldest community of organisms on the earth ' (Sir John 
Murray). The special feature, however, is the presence 
here of some Arctic Crustacea, and the absence of certain 
forms found in other European lakes, both no doubt 
due to the northern position of the lochs. 

As has been just stated, the lochs are mostly shallow, 
and therefore an abyssal fauna is rarely developed. 
Of the two deep lochs, only in Loch Ness were successful 
deep-water dredgings made. Here it was found that at 
depths greater than 300 feet the majority of the httoral 
species disappear, leaving a small group of animals, 
including one mollusc (a small bivalve called Pisidium 
pusillum), three Crustacea, three worms, an insect larva, 
and a few infusoria. These occur also in the httoral 
region, and the forms from deep water show no special 
feature, so that it would be more correct to say that 
a few only of the littoral forms can live in depths 
greater than 300 feet than to say that a special deep- 
water fauna exists. 

Before leaving the fauna of these lakes, one interest- 
ing point may be noticed. In certain of them, especially 
those which lie but little above sea-level, a marine 
crustacean caUed the opossum shrimp (My sis) occurs. 
In the Scottish lochs the species of Mysis found is that 



THE ANIMALS OF LAKES AND RIVERS 199 

which also occurs round the coasts in salt and brackish 
water, and its presence is doubtless to be explained on 
the supposition that it is a recent migrant from the 
sea. But in certain continental lakes, especially those 
in Denmark and on the North German plain, another 
variety or species occurs, called Mysis relicta. The 
modifications which this form displays are believed to 
indicate that the bodies of water in which it occurs 
were once connected with the sea, but have been long 
separated from it. Such organisms are said to con- 
stitute a relict fauna, and the lakes in which they occur 
are called relict lakes (German, Reliktenseen), to indi- 
cate their supposed former connexion with the sea. 

With the Scottish lochs may be contrasted Lake 
Balaton or Flatten See, a large shallow body of water 
in Hungary, connected with the Danube drainage 
system. The area of this lake is about 250 miles, but 
its average depth is only 10 feet, and the maximum 
36 feet. Its fauna has been subjected to detailed 
investigation. 

As its shallowness makes Lake Balaton a mere pool, 
we find that here the fauna forms a unity. Necessarily 
there is no deep-water fauna, and it is not possible to 
discriminate accurately between littoral and pelagic 
faunas, as the bottom is everywhere so close to the 
surface. The total number of species does not differ 
greatly from that of the Scottish lochs, being about 
475, including 38 kinds of fish, but exclusive of insects 
and air-breathing vertebrates. The fish show some 
interesting peculiarities. There are no trout, but the 
lake contains such common fresh-water forms as perch, 
gobies, pike, eels, roach, tench, gudgeon, &c., and in 
addition two forms of special interest. One is the cat- 
fish called ' Wels ' by the Germans {Silurus glanis), 



200 THE ANIMALS OF LAKES AND RIVERS 

and the other the sterlet {Acipenser ruthenus). Tlie 
cat-fish constitute a large family of fresh-water fish 
especially characteristic of the equatorial region. The 
wels is found only in Eastern Europe, and is the only 
member of its family in European waters. The sterlet 
is a near ally of the sturgeon, and is a member of 
a small group of old-fashioned fishes which used to 
be called ganoids. The name has been abandoned in 
more recent classifications of fish, for the ganoids are 
not a homogeneous group, but their interest for us is 
that they are fish of a primitive type, which once lived 
in the sea, but have been driven into fresh water 
(though the sturgeon also occurs in the sea) by the 
competition of the more highly organized bony fish. 

Of the invertebrates it is sufficient to say that 
with considerable general resemblance to those of the 
Scottish lochs, they display certain minor differences. 
Thus, the Arctic types of Crustacea are absent, and 
such forms as the fresh-water crayfish (Astacus), found 
in England, but not in Scotland, are present here. 
Similarly there is a greater wealth of moUuscs, a con- 
siderable number of genera of more or less southern 
facies being here represented, though they are absent 
from the lochs of Scotland. On the other hand, the 
rotifers are far less abundant than in the Scottish lochs, 
but comparisons of this sort do not profit very much, 
as it is difficult to be sure that the investigations have 
been conducted along exactly similar lines in the two 
cases. 

As a third example of a lake fauna we may take that 
of Lake Tanganyika in tropical Africa, which has been 
the object of careful study by Mr. J. E. S. Moore 
and others. 

Tanganyika has an area of 12,700 square miles. It 



THE ANIMALS OF LAKES AND RIVERS 201 

has never been systematically sounded, but depths of 
1,200 to 2,100 feet have been recorded at various 
localities. The elevation is 2,624 feet above sea-level. 
The fish fauna show some curious features. In the 
first place the lake contains a species of Protopterus, 
one of the three living genera of dipnoi or lung-fishes. 
The two other living genera inhabit the one (Lepido- 
siren) the rivers of tropical America, and the other 
(Ceratodus) those of Queensland. As well as occurring 
in Lake Tanganyika, the species of Protopterus have 
a wide distribution in the lakes and rivers of the middle 
portion of the African continent. All the dipnoi 
possess, as we have seen, both lungs and gills, but the 
two sets of breathing-organs are not in use simul- 
taneously. The fish normally inhabit regions where a 
periodical dry season occurs, when the water in which 
they live either becomes very foul or dries up. The 
first condition is frequent in the natural habitat of the 
Queensland Ceratodus, the second in that of the two 
other genera. At this period, therefore, Lepidosiren and 
Protopterus make themselves nests of mud, in which 
they lie dormant, breathing by their lungs till the 
water returns. In the case of Ceratodus the lungs are 
used when the water is too foul for the gills to be of 
any use, but the animal does not make mud nests. All 
three genera show certain very primitive characters 
in combination with this specialized mode of breathing. 
Their ancestors were certainly marine, many fossil 
forms having been found. Thus the dipnoi must be 
looked upon as the fresh-water survivors of a highly 
primitive group of marine fishes, owing their per- 
sistence to the acquisition of specialized breathing- 
organs. Their ' discontinuous distribution ' over the 
surface of the globe is another point of interest in 



202 THE ANIMALS OF LAKES AND RIVERS 

regard to them. Such discontinuity is common with 
old-fashioned animals, which owe their local persis- 
tence to their adaptation to special environmental con- 
ditions. The tapir in the swampy forests of the Malay 
region and in South America, but nowhere else, is 
another example. 

Another very peculiar fish-type in Tanganyika is 
Polypterus congicus, a member of a ' ganoid ' genus, 
which is restricted to tropical Africa. Like Protopterus 
this fish has an accessory respiratory organ, for the 
organ which forms the air-bladder in many other fish 
seems here to be used in respiration, perhaps because 
the fish inhabits the same regions as Protopterus, i.e. 
rivers whose waters become periodically foul. In very 
many points of structure, however, the species of 
Polypterus differ markedly from those of Protopterus. 
Into these points we cannot go here, but it may be 
sufficient to say that many zoologists are of opinion 
that they show that terrestrial vertebrates arose from 
a stock common to them and to Polypterus. Though 
the lung of the dipnoi is much more like the lung of 
a terrestrial vertebrate than is the air-bladder of 
Protopterus, it is not believed that dipnoi are near the 
line of descent of terrestrial vertebrates, largely because 
of the structure of their limbs. It seems as if the limb 
of Polypterus could more easily give rise to that of 
a land vertebrate than that of Protopterus. We have 
already considered several cases of land animals re- 
acquiring modifications of structure which fit them for 
life in the water, but Polypterus is interesting as sug- 
gesting one way in which land ar^imals arose from 
aquatic ones. Its ancestors were certainly marine, 
but were driven into fresh water by the competition 
of better-organized forms which appeared in the sea. 



THE ANIMALS OF LAKES AND RIVERS 203 

The relatively unfavourable conditions which exist in 
rivers made it necessary to develop accessory breathing- 
organs, and these apparently led the way to the acquisi- 
tion of purely terrestrial characters, in the allies of the 
ancestral Polypterus. 

Another peculiarity of the fish fauna of Tanganyika 
is the enormous number of fish belonging to the family 
Cichlidae. The lake is characterized by its very large 
number of fish, nearly a hundred different species 
having been described. Of these, more than half 
belong to the family Cichlidae, and, more remarkable 
still, of the fifty-eight species of this family described 
in the lake only one is known outside the lake. We have 
already noted, in speaking of the Scottish lakes, that 
it is not unusual to find peculiar varieties or species of 
fish in lakes, but the fact that many peculiar genera 
occur in Tanganyika speaks to long isolation. 

The other fish of the lake are for the most part 
similar to those which occur in the remaining African 
lakes. For instance, there are a considerable number 
of cat-fish, very usual inhabitants of equatorial lakes. 
As we shall see directly the invertebrates show the same 
general pecuHarities as the fish — that is, we find a com- 
bination of forms found in other African lakes, and of 
quite peculiar forms of primitive type, the result being 
to give the lake an unusually large fauna. Moore 
believes that this shows that the lake had once a direct 
connexion with the sea to the west, through what is 
now the Congo basin. He places the rupture of this 
connexion so long ago as the period called by geologists 
the Jurassic, and believes that at the time of the 
rupture the lake was peopled by Jurassic forms. These 
in course of time evolved into the peculiar types 
now found in the lake, which retain many archaic 



204 THE ANIMALS OF LAKES AND RIVERS 

characters. Later, the ordinary fresh-water fauna of 
Africa gradually reached the lake, giving the present- 
day ininghng of special types with marine affinities 
(haloHmnic forms) and ordinary fresh-water types. This 
hypothesis has not been universally accepted, and the 
evidence upon which it is based depends upon detailed 
anatomical points which cannot be considered here. 

As the figures already given suggest, Tanganyika is 
an enormous lake when compared with the lochs of 
Scotland, and it is of course very inaccessible. We 
cannot, therefore, hope to have the detailed information 
in regard to its fauna which is available for the Scottish 
lochs or for Lake Balaton. It has never been systematic - 
ally sounded, so that it is not possible to distinguish 
between the faunas of the different depths in detail. 
The great point of interest is the occurrence of inverte- 
brate animals of defuiitely " marine ' type, notabty of 
a fresh-water jellyfish. Invertebrates of marine type 
are of course not confined to Tangamdka. We have 
already mentioned their occurrence in other lakes, e.g. 
in Lake Baikal, but they seem to be especially numerous 
and peculiar in Tanganyika, and, as already stated, 
they coexist there with ordinary fresh-water forms. 

No less than fifty species of molluscs have been 
described from Lake Tanganyika. Of these a con- 
siderable number belong to the genera commonly 
represented in masses of fresh- water elsewhere. Thus 
we have species of Limnaea, Planorbis, Bithynia, Unio, 
&c., the first two genera being cosmopohtan and very 
old. But in addition there are a number of gastropods 
of pecuhar and primitive characters, with strong marine 
affinities, constituting part of Moore's ' hgJohmnic " 
fauna. Some of these five at depths of 600 feet and 
upwards, which is in itself an exceptional feature, for, 



THE ANIMALS OF LAKES AND RIVERS 205 

as we have already explained, there appears to be a 
deficiency of oxygen in the depths of equatorial lakes, 
and in Lake Nyasa no life has been found at depths 
greater than 100 to 150 feet. The occurrence of deep- 
water forms in Lake Tanganyika is perhaps associated 
with the antiquity of the lake, which has given time 
for the evolution of a special deep-water fauna. 

The Crustacea include the usual small copepods of 
fresh water, and also two crabs and two prawns, all 
pecuhar to the lake. One of these crabs extends down- 
wards from 500 to 600 feet, and is thus another example 
of the deep-water fauna. Among the other interesting 
forms are a peculiar polyzoon, three fresh-water sponges, 
and the jellyfish (Limnocnida) already mentioned. A 
closely related fresh- water jellyfish has been described 
from Rhodesia, and another apparently very similar 
form has been found in the tributaries of the Krishna 
in India, but none of these is well known. 

The protozoa of Tanganyika seem to resemble 
generally those of other African lakes, and indeed those 
of lakes in general. 

To these accounts of characteristic lake-faunas, a 
word or two may be added on the fauna of the Great 
Salt Lake of Utah. Here the conditions are extra- 
ordinarily unfavourable to animal life. Only one 
organism can be said to have solved completely the 
problem of adaptation to life in the brine. This is the 
Brine-shrimp {Artemia salina), which in summer is 
excessively abundant (cf. Scottish Geographical Magazine, 
vol. xvii. (1901) p. 617). It is very tolerant of cold 
and of variations in the salinity of the water, and the 
fact that the eggs can develop parthenogenetically — that 
is, without previous fertilization — enables the animals to 
reproduce themselves very rapidly when the conditions 



206 THE ANIMALS OF LAKES AND RIVERS 

are at all favourable. During the warm season the 
larvae of two flies, a Tipula and a Chironomus, also 
occur in the shore waters, and a water-boatman (Corixa) 
is also found in the lake. Otherwise it is singularly 
barren of animal life. 

Cave Faunas. As caves usually contain a consider- 
able amount of water, something may be said here of 
the more characteristic animals found in them. Cave 
animals live in conditions which in many respects 
resemble those prevailing in the ocean abysses. Thus 
there is often complete darkness, and the temperature, 
though it may be low, is remarkably uniform. Green 
plants, also, are necessarily absent. Some of the charac- 
ters of abyssal forms therefore reappear here ; for 
example, the eyes tend to disappear or become minute. 
But as the light conditions are quite different from 
those which obtain in the ocean depths, where as we 
have seen (p. 172) certain rays penetrate deeply, we 
find that cave animals tend to be white, instead of 
showing the deep-red or black coloration found in 
many animals which live in the ocean near the light 
limit. 

An interesting example of a cave animal is Proteus 
anguinus, found in the caves of Carniola, Dalmatia, 
and Carinthia. This animal is one of the permanently- 
gilled amphibians already described, and reaches a 
length of about a foot. The skin is without pigment, 
and the eyes are below the skin. The animal remains 
permanently within the water, though it rises to the 
surface to breathe if the water is not quite pure. 
Curiously enough, if the white body is exposed to hght 
pigment develops in the skin, and perfectly black 
specimens can be produced by gradual exposure. In 
the caves of Texas there is an allied form {Typhlomolge 



CAVE FAUNAS 207 

raihhuni) of similar characters. The same type of 
adaptation also reappears among the cave fish, which 
have been especially studied in the Mammoth Cave of 
Kentucky. One of the most interesting found there is 
Amblyopsis spelaea, which is white in colour, and has 
concealed eyes. To make up for the loss of the eyes 
the head is furnished with a great number of tactile 
papillae. 

Of other cave animals the most important are Crus- 
tacea, especially isopods, e.g. Titanethes albus, which 
has no eyes, and insects, notably beetles, e.g. Adelops 
and Bathyscia, also some spiders, myriapods, and a few 
molluscs, the tendency to lose eyes and the pigmenta- 
tion of the skin being well marked. 

References. The first volume of the scientific results of the Bathy- 
metrical Survey of the Scottish Fresh-water Lochs, conducted under the 
direction of Sir John Murray and Laurence Pullar (Edinburgh, 1910), 
contains several articles dealing with the fauna of lakes, as mcII as 
detailed lists of the organisms found in the Scottish Lochs. This volume 
gives also a detailed bibliography of limnological literature. The account 
of the fauna of Lake Balaton given in the text is based upon the Besultate 
der wissenschaftlichen Erforschung des Balatonsees, herausgegeben von 
der Balatonsee-Commission der Ungarischen Geographischen Gesellschaft 
(Vienna, 1906). A full account of the fauna of Lake Tanganyika is 
given in The Tanganyika Problem, by J. E. Moore (London, 1903). 
Other references to the same subject will be found in the bibliography 
mentioned above. Many of the general works already mentioned also 
discuss fresh-water faunas, and to them may be added Forel's Handbuch 
der Seenkunde (Stuttgart, 1901), and the same author's large work on 
Lake Geneva (Le Leman : Monographic limnologique, 1892-1904, Lau- 
sanne), and Die Tier- und PJlanzenweU des Sllsswassers, by Dr. Otto 
Zacharias and others (Leipzig, 1891). See also articles on the river 
mussels, &c., of South America in Archhelenis u. Archinotis, by Hermann 
von Ihering (Leipzig, 1907). Kobelt's book (cf. p. 35) has an interest- 
ing chapter on cave faunas. See also Semper's Conditions of Existence 
as they affect Animal Life (London, 1881). The blind fish of the Kentucky 
cave are discussed by Putnam {Amer. Nat. 1872). 



CHAPTER X 
ZOOGEOGRAPHICAL REGIONS 

We have now surveyed those natural regions of the 
earth described in the Introduction, and have noted 
their more important occupants, and the adaptations 
which these show to their particular habitats. In the 
course of these descriptions it has become obvious that 
what may be called the raw material upon wliich 
adaptation has worked is not the same in all parts of 
the globe. We have found that animals inhabiting 
dense forest generally show certain arboreal adaptations, 
such as the prehensile tail, the opposable thumb and 
great toe, and so forth, found wherever the forest 
occurs. But in New Guinea, for example, certain 
kangaroos have taken to the trees and become arboreal ; 
in Madagascar lemurs swarm in the forests ; in South 
America particular kinds of monkeys, the opossums, 
and the sloths, as well as other animals, people the 
selvas, and so on. In other words, each isolated forest, 
or other area, has its own types of adapted animals. 

The only possible explanation of these conditions is 
the hypothesis that the speciahzed forms in each 
separate region have been evolved from pre-existing 
unspeciahzed forms inhabiting the region. In South 
America we find fossil representatives of ground sloths. 
These have long since become extinct, and the exist- 
ing sloths have apparently been saved from a hke 
fate by the acquisition of marked arboreal characters, 
which protect them from many possible enemies. In 
the continent of Australia, and parts of the adjacent 



ZOOGEOGRAPHICAL REGIONS 209 

regions, kangaroos are abundant, and are for the most 
part savana animals. But where tropical forests occur, 
as in North Queensland and New Guinea, there certain 
forms have taken to the arboreal life, and have thus 
protected themselves from the competition of ground- 
living forms no less than from the attacks of some 
possible enemies. 

The same statements might be made of desert 
animals, of savana animals, or, generally, of any 
forms inhabiting a natural region. We may say, then, 
that when any stock of terrestrial animals reaches a 
new region, and is there isolated from any cause, that 
stock will tend to give rise to specialized groups, more 
or less perfectly adapted to all the possible varieties 
of habitat which the region affords. In order that 
a particular stock may give rise by specialization and 
differentiation to many such groups, some degree of 
isolation seems to be necessary, for otherwise new 
incoming stocks may colonize the vacant places before 
the first stock has had time to become differentiated. 
For example, in Australia almost all habitats suited 
to terrestrial mammaUa are occupied by marsupial 
animals. Living marsupials also occur in South 
America, but there they are represented by a very 
limited number of types, because they have had to 
face the competition of placentals, practically absent 
in AustraUa. Similarly, in Madagascar the lemurs are 
very numerous and very diverse, being adapted for 
different modes of life. Lemurs also occur in Africa 
and India, but there, where they have to face the com- 
petition of the more intelligent monkeys, and the 
attacks of more powerful carnivores than any which 
are found in Madagascar, they are few in number, 
small in size, and less diverse. 

1404 O 



210 ZOOGEOGRAPHICAL REGIONS 

Such isolation of portions of the earth's surface is 
caused by the existence of barriers to the distribution 
of terrestrial animals. Necessarily these barriers must 
be supposed to have a definite date of origin, and 
this origin must always be supposed to be later in 
time than that of the ancestral stock of the group 
under consideration, but to precede the differentiation 
of the stock into many divisions as the result of the 
isolation. As an example of the origin in time of such 
a barrier let us take a progressive climatic change. 
The animals of temperate Europe and Asia show 
a marked difference from those of tropical Asia and 
of tropical Africa. To some extent this difference is 
doubtless due to the existence of transverse mountain- 
chains, such as the Himalayas and the Andes, but it 
is also largely due to the existence of a great band of 
deserts and wastes across Asia and Northern Africa, for 
both the mountains and the deserts prevent intermixmg. 
Now there is much evidence to show that there has 
been a progressive desiccation in this region within 
geologically recent times. One effect has been to 
favour the development of the many steppe and desert 
animals of the region, but another has certainly been 
to separate an originally homogeneous fauna into three 
parts, and by isolating much of Africa on the one hand 
and the peninsula of India with Further India on the 
other, to favour evolution in these two areas, now pro- 
tected from the incursion of northern forms, save on 
a very limited scale. We have seen, for example, how 
scantily represented in temperate Europe and Asia 
are the abundant antelopes of Africa, and similarly 
how the numerous deer of the north are shut out from 
Africa by the, to them, impassable desert. 

To the zoogeographer, however, the greatest barrier 



ZOOGEOGRAPHICAL REGIONS 211 

is undoubtedly the sea, for a broad channel offers an 
insuperable barrier to the passage of most land animals, 
save those small enough, or resistant enough, to be 
carried passively by winds and waves or an animal 
host. Here, obviously, we approach difficult questions. 
Geological research, especially in recent years, has 
familiarized geographers with the idea that great 
changes in the distribution of land and water have 
taken place on the surface throughout geological time. 
Now to consider this distribution in its relation to 
animal life and evolution from the Cambrian period 
onwards would obviously be a Herculean task, though 
it is one which has been attempted, e.g. by Arldt. 
Without such a consideration, however, we cannot 
hope to explain in its entirety the distribution of 
animals at the present time. But without attempting 
to do this, it is of interest to note the main features 
of the distribution of the higher forms of Ufe in the 
existing continental masses. As we saw in the Intro- 
duction, such a division of the globe into zoogeo- 
graphical regions is primarily of interest to the zoologist 
rather than to the geographer. This is especially true 
when the subject is treated in detail, as in most of the 
works on the subject. At the same time for historical 
reasons, if for no other, the subject is too important 
to be entirely omitted, and in this concluding chapter we 
shall consider briefly the classical ' regions ' into which 
the globe has been divided by zoologists, on the basis 
especially of the distribution of birds and mammals. 

In dividing up the globe in this way the first point to 
be emphasized is that, though the geographers are accus- 
tomed to lay great stress upon the distinction between 
the American and Eurasiatic continents, between 
the Old and the New Worlds, no such distinction 

o 2 



212 ZOOGEOGRAPHICAL REGIONS 

exists between the animals, at least of the northern 
regions. We have already pointed out that the tundra 
animals of the east and west show very marked resem- 
blances to one another ; that similarly there is con- 
siderable resemblance as regards both the plants and 
animals of the belt of coniferous forest in both hemi- 
spheres, and that only as we travel southwards does 
differentiation appear. There is much evidence, both 
geological and zoological, to show that not long ago there 
was free land communication between the Old and New 
Worlds in the northern hemispheres, across what is 
now the Bering Strait, as well as possibly across parts 
of the North Atlantic. Further, though parts of what 
are now the continents of Africa and of India were, 
in early Tertiary times, probably separated by stretches 
of sea from the land-masses to the north, and though 
they are now functionally separated from the great 
land-mass in the eastern temperate and frigid zones 
by belts of deserts and by tralisverse mountain-chains, 
yet, before the progressive formation of these belts of 
desert, there was apparently a time when it was 
physically possible for land animals to spread from 
the far north of Europe and Asia to the far south of 
Africa and India, and south-eastwards to parts of 
the Malay Archipelago. With this great eastern land- 
mass North America, as already suggested, was in 
free communication, though it seems to have been leng 
separated from South America. 

We thus have to consider as forming one great 
Realm of the earth's surface the whole Eurasian con- 
tinent with parts of the Malay Archipelago, the con- 
tinent of Africa with the isolated region of Madagascar, 
and North America. In this great land-mass evolu- 
tion, as we would expect from its great extent, has been 



ZOOGEOGRAPHICAL REGIONS 213 

rapid. Here we find the highest mammals and the 
most speciaHzed birds. Where the tropical forest is 
dense a few primitive forms linger, and some also have 
been saved by isolation, e.g. in Madagascar. But as 
a general rule the primitive forms have been crushed 
out of existence by higher forms. No marsupial (save 
one opossum in North America) now lives within this 
great area, and no monotreme. No primitive reptile, 
like the Hatteria of New Zealand, points us back to an 
earlier age. Here and here alone do we get the highest 
of the primates apart from man — the anthropoid apes 
and the dog-faced baboons. Here and here alone do 
we get the highest and most specialized of the ungulates, 
and so on. 

For this great area various names have been pro- 
posed. Thus it has been called Arctogaea, or the 
Northern World, because of its mainly northern position, 
though Africa extends far to the south. 

In regard to the boundaries of this realm it may be 
said that over much of the area they are formed by 
the sea. In two regions, however, difficulty occurs. 
One is in the south-east, where a boundary line has to 
be drawn through that mass of islands which stretches 
between Further India and the northern shores of 
Australia. Wallace drew the line which separates his 
Oriental (or Indian) region and the AustraHan region 
between the islands of Bali and Lombok. A narrow 
but deep strait separates these islands, and Wallace 
believed that all the islands to the east of this strait 
(Wallace's line) possessed faunas with a distinctively 
Australian facies, while those to the west had faunas of 
Indian type. Recent detailed research has thrown 
some doubt upon this statement. A mingling of 
faunas certainly occurs in this region, and any hard 



214 ZOOGEOGRAPHICAL REGIONS 

and fast line must necessarily be of a more or less 
artificial character. The difficulty is sometimes got over 
by the erection of a transitional region. It is enough 
for our purpose to know that such a transition exists. 

The other area where a fine is difficult to draw is 
in the American continent. There are many striking 
differences between the faunas of North America and 
South America, but the two regions are now in free com- 
munication. Necessarily, therefore, a certain amount 
of minghng occurs. That this mingling is not greater 
than it is is doubtless due to climatic differences, to 
the occurrence of desert regions, e. g. in Mexico and the 
west, and so on. Here again the difficulty is usually got 
over by the erection of a transitional region to include 
a considerable part of the south-western United States. 

The rest of the globe is sometimes included in one 
Realm, forming the Notogaeic Realm, or Southern 
World, and including on the one hand Southern and 
Central America, with Mexico and the West Indian 
islands, and on the other the continent of AustraUa 
with Tasmania, New Guinea, the islands of New 
Zealand, and some of the islands of the Malay Archi- 
. pelago, as weU as the scattered groups of Polynesia. 
This union of Australia and South America, despite 
their considerable separation in space, seems to be 
justified by the increasing proofs of the affinities of 
their faunas, and the increasing probability that they 
were connected, at a not very remote period, through 
the Antarctic continent. 

The Notogaeic realm so defined is characterized by 
the presence of monotremes (in Austraha) and mar- 
supials ; by the presence of running birds and dipnoi 
(these being characters shared with Africa), and by the 
absence of the highly differentiated forms named above. 



ZOOGEOGRAPHICAL REGIONS 215 

Now it is obvious that these two realms are large 
and unwieldy divisions. They are therefore in their 
turn subdivided into regions. Taking the Arctogaeic 
realm first, we find that it may be subdivided into the 
following regions : (1) the Holarctic, including the 
whole of temperate Europe, Asia, and North America ; 
(2) the Oriental, including India south of the Hima- 
layas, Further India, and parts of the Malay Archi- 
pelago ; (3) the Ethiopian, including Africa south of 
the Atlas and Sahara desert. To these many would 
add a fourth region for the island of Madagascar, whose 
fauna is so strikingly difl^erent that it may well form 
(4) the Malagasy region. But while the fauna of the 
Oriental region shows many resemblances to that of 
the Holarctic region, the differences being largely 
attributable to differences of climate, Africa, in the 
characters already mentioned, is strikingly dissimilar, 
and approaches the South American and Australian 
regions. Without pursuing this point further, we may 
note that some authorities separate it on this account 
from the Arctogaeic realm. 

Again, the Notogaeic realm obviously falls into two 
regions : (5) the western or Neotropical, and (6) the 
eastern or Australian. 

This classification may be summed up in tabular 
form as follows : 

ARCTOGAEIC REALM. 

(1) Holarctic region [sometimes divided into an 
eastern (Palaearctic) and a western (Nearctic) sub- 
region]. 

(2) Oriental region. 

(3) Ethiopian region. 

(4) Malagasy region. 



216 ZOOGEOGRAPHICAL REGIONS 

NOTOGAEIC REALM. 

(5) Neotropical region. 

(6) Australian region. 

Each of these regions may now be considered in 
a Httle detail. 

Beginning with the Holarctic region, we find that 
the western or Nearctic section has no primates, and 
the eastern or Palaearctic only those species of Semnopi- 
thecus and Macacus already mentioned (pp. 77-8). In the 
Palaearctic section the sheep and goats are well repre- 
sented, but to the west they are few (cf. p. 82). Both 
sections have oxen. The antelopes are scantily repre- 
sented in both, while deer are abundant. To the east, 
but not in the west, camels and horses occur. Elephants 
do not occur in either division, but both are rich in carni- 
vores. Ainong the special forms it is noticeable that 
the badger is peculiar to the Old World, while the 
Nearctic section shares the skunk and raccoon with the 
Neotropical region. In' both divisions rodents are very 
numerous, but this is a fact which has already been 
sufficiently discussed. Among the insectivores the 
mole (Talpa) is a form peculiar to the Old World, 
where it extends into the Oriental region. 

The bird faunas of the two regions differ from each 
other somewhat markedly, but this is partly because 
both regions receive many seasonal immigrants from 
the hotter land-masses lying to the south of them. 
The differences also chiefly affect genera or even species, 
rather than orders or families. Two familiar families 
of the Old World are, however, absent in the New. 
Thus North America has no true starlings, their place 
being taken by the hang-nests or Icteridae, to which 
the rice-bird or bobolink (Dolichonyx) belongs. The 



ZOOGEOGRAPHICAL REGIONS 217 

flycatchers (Muscicapidae) of the Old World are also 
absent in the New, their place being taken by the 
tyrant shrikes (Tyrannidae). Reptiles are somewhat 
scantily represented, but we have already touched 
upon the abundance of tailed amphibians, the majority 
of which are peculiar to the region. Something has 
also been said of the fresh-water fish fauna, which is 
remarkable for its development of salmon, carp, pike, 
perch, sticklebacks, &c. There is nothing specially 
worthy of note as regards the invertebrates. 

The animals of the Oriental region show so marked 
a general resemblance to those of the Ethiopian, that 
some naturalists would unite the two as a Palaeo- 
tropical region. There are, however, certain well- 
defined differences in addition to basal resemblances. 

Beginning with the Primates, we find that the Oriental 
region has two peculiar kinds of anthropoid apes, the 
orang of Sumatra and Borneo, and the gibbons of the 
Malay region. There are also many kinds of monkeys, 
belonging to the genera Macacus and Semnopithecus. 
The genus Cynopithecus includes only one species, the 
so-called black ape, peculiar to the island of Celebes, 
usually included in the Oriental region. We have 
already mentioned the peculiar proboscis monkey 
(Nasalis) of Borneo. There are four lemurs, including 
two species of the very peculiar genus Tarsius. In the 
continent of Africa there are eight species, and in 
Madagascar about thirty-six species — a very interest- 
ing contrast. 

The Oriental region is rich in bats, having many 
representatives both of the insect-eating and the fruit- 
eating forms, with some peculiar genera. 

Among the insectivores the very peculiar flying 
lemurs (Galeopithecus) of the Philippine Islands are 



218 ZOOGEOGRAPHICAL REGIONS 

confined to the region, as are also the tree-shrews 
(Tupaia). 

Carnivores are numerous, and among the interesting 
contrasts with the Ethiopian region is the presence of 
bears, beheved to have originated within the Oriental 
region. The tiger, whose presence in India affords 
another point of contrast with Africa, does not reach 
Ceylon, and is believed to be a relatively recent immi- 
grant into India. Like the Ethiopian region, the 
Oriental one is rich in civets and their allies. True 
cats of the family Felidae are also numerous. 

Among the ungulates we note the presence of oxen, 
the paucity of antelopes, the abundance of deer, the 
presence of chevro tains, of many pigs, of rhinoceroses, 
of a tapir, and an elephant, and the fact that wild 
asses just reach the region. 

Rodents, especially squirrels and mice, are abundant, 
and include peculiar genera. The Edentates are repre- 
sented by members of the genus Manis, the pangolins, 
represented elsewhere only in the Ethiopian region. 

Birds are very numerous, the region being especially 
characterized by the number and beauty of its pheasants. 
On the other hand, parrots are relatively few, com- 
pared with their abundance in the Austrahan region. 
The babbling thrushes (Timehdae) have their head- 
quarters in the region, and are very numerous. Very 
striking also are the bulbuls (Pycnodontidae), green 
bubuls (Phyllornithidae), and the hill-tits (Leiotrichidae). 
There are many reptiles ; we have already spoken of 
the flying Kzard (Draco) and the crocodiles. The long- 
snouted forms of the latter (Gaviahs) are restricted to 
the region, where there is one species in the Ganges. 

A good many of the peculiarities of the Ethiopian 
region have been alluded to incidentally in the fore- 




Fig. 45. Clouded Leopard of S.E. Asia. (From the picture hy W. Walh.) 




Fig. 46. The Okapi. {From a specimen in the Royal Scottish Museum.) 



ZOOGEOGRAPHICAL REGIONS 219 

going description, but some further details may be 
added. The region is almost equally characterized by 
the forms which are present, and by those which are 
absent. Among the Primates it possesses the gorilla 
and the chimpanzee, two peculiar forms confined, as 
we have seen, to a relatively small part of the con- 
tinent. Monkeys are represented by five peculiar 
genera with many species, lemurs by two or three 
genera and some eight species. Fruit-bats are fewer 
than in India. Insectivores are peculiar and primitive. 
Thus we have jumping-shrews, the aquatic potamogale 
and the golden mole, the latter beheved to be alhed 
to the curious tailless hedgehog or tenrec of Madagascar. 
Among the carnivores an interesting feature is the 
presence of two peculiar dogs, belonging to the two 
genera of Lycaon and Otocyon, the latter having very 
primitive teeth. We have already spoken of the 
absence of bears, and it is noticeable that the weasel 
alliance is scantily represented. 

So much has been already said of the ungulates (p. 129 
et seq.) that a few general statements may suffice. 
Goats and sheep are practically absent, and with one 
exception so are true pigs of the genus Sus, though wart 
hogs, bush pigs, river hogs, and the hippopotamus occur. 
There is no tapir and no camel, but rhinoceroses, 
elephants, chevrotains, and several kinds of horses 
occur, as well as the curious hyrax and pecuHar forms 
Uke the giraffe and okapi ; antelopes are abundant. 

In regard to the rodents a peculiar feature is the 
absence of the true flying squirrels and their replace- 
ment by the peculiar family of Anomaluridae (cf . p. 109). 
The Edentates are represented by the curious aard-vark 
(Orycteropus), as well as by pangoHns. 

The birds are not so abundant nor so beautiful as 



220 ZOOGEOGRAPHICAL REGIONS 

those inhabiting the Oriental region. The plantain- 
eaters (Musophagidae) and the colies (Coliidae) are 
among the peculiar families. Though the beautiful 
sun-birds (Nectarinidae) are represented in the Oriental 
and Australian regions, they are especially charac- 
teristic of Africa, where they take the place of the 
humming-birds of South America, which they somewhat 
resemble in beauty of plumage and in habits. Parrots 
are not very numerous. The true ostrich, though not 
confined to the region, is very characteristic. Reptiles 
are numerous, and among the fish we have to note the 
presence of the dipnoan genus Protopterus, and the 
curious ' ganoids ' known as Polypterus and Cala- 
moicthys. Some other peculiarities of the fresh- water 
fauna have been already alluded to. 

The Malagasy region or sub-region (p. 152) shows 
some very striking differences from the mainland, 
these differences testifying to its long isolation. Thus 
there are no anthropoid apes nor monkeys, but some 
thirty-six species of lemurs occur, all belonging to 
peculiar genera. The insectivores are somewhat 
numerous, for there are over twenty species. The 
relative abundance of these and of lemurs, both help- 
less forms, must be associated with the paucity and 
small size of the carnivores. Of the insectivores all 
save one species of musk-shrew (Crocidura) belong to 
peculiar genera, and most belong to a peculiar family, 
that of the tenrecs or Centetidae, which is entirely con- 
fined to the island, and shows many primitive charac- 
ters. The musk-shrews are widely distributed in the 
Old World, and the genus is one of the three which 
Madagascar shares with the adjacent mainland. The 
other two are hippopotamus (with one extinct species) 
and Potamochoerus, the river hog (with one species) 



ZOOGEOGRAPHICAL REGIONS 221 

Rodents are represented by five peculiar genera belong- 
ing to the mouse section ; carnivores by some seven 
members of the civet family, of which the largest is 
the cat-Hke animal called Cryptoprocta. All the genera 
of camivora are peculiar to the island. The absence of 
the true cats of the genus Felis, elsewhere so widely 
distributed, is a remarkable feature. 

The above include all the non-fljdng mammals of 
Madagascar, and it will be noted that they form 
a striking contrast with those of Africa. The charac- 
teristic African birds, e.g. the plantain-eaters and 
colies, are similarly absent, while the reptiles are very 
remarkable in that some show affinity with those of 
South America rather than with those of Africa. The 
chameleons present some interesting features. These 
lizards occur in Africa and in India, but are more 
abundant in the island of Madagascar than anywhere 
else, thus showing a curious parallelism with the lemurs. 

Turning now to the Notogaeic Realm we may begin 
with the Neotropical region, which is both highly 
pecuHar and very rich in species. Here are no anthro- 
poid apes, no dog-faced (Catarrhine) monkeys, and no 
lemurs, but on the other hand a peculiar family of 
broad-nosed (Platyrrhine) monkeys, and another of 
small, also broad-nosed, furry forms called marmosets, 
both families differing in a number of respects from all 
the Old World forms. The bats are very peculiar. Here 
only (with a slight extension into North America) do 
we find the vampire bats, while the fruit-bats of the 
Old World are completely absent, as well as another 
family called the horse-shoe bats (Rhinolophidae), 
Insectivores are practically absent, though in the West 
Indian Islands there occur two shrews of the genus 
Solenodon, believed to be related to the Centetidae of 



222 ZOOGEOGRAPHICAL REGIONS 

Madagascar. Of the carnivores it is only necessary to 
say that bears are represented by only one species, 
while raccoons are plentiful, and like the skunks are 
common to this region and the Nearctic. 

Very remarkable conditions are exemphfied by the 
ungulates. We find pecuhar deer, pecuhar pigs (pec- 
caries), tapirs (shared with the Malayan region), llamas 
(aUies of the Old World camels), but no antelopes, 
sheep, goats, oxen, nor horses. There are many peculiar 
fossil forms, but these are beyond our range. 

We have already spoken of the number and peculiar 
nature of the rodents, and nothing need here be added 
to what has been said on pp. 56 and 87. The pecuhar 
nature of the Edentates has also been pointed out, and 
the presence of many kinds of opossums. In South 
America there occur also other marsupials, known as 
selvas (Coenolestes), which are of great interest because 
they are beHeved to belong to the herbivorous or 
diprotodont section, that of which the kangaroo is the 
most familiar representative. The discovery of these 
Uttle animals in South America is of great theoretical 
importance, because it was formerly beHeved that 
the diprotodont marsupials had originated within the 
Austrahan area, and had never occurred outside it. 
Their existence, therefore, is another link in the increas- 
ing chain of evidence which points to a former con- 
nexion between South America and AustraUa. 

The birds of South America are almost as pecuhar 
as the mammals, though, as was to be expected, many 
of the characteristic forms extend also into North 
America. Among the important famihes are the 
humming-birds, the macaws (Conurinae), the toucans, 
the jacamars, the motmots, the chatterers, the tanagers, 
the tinamus (cf. p. 140), the curassows (Cracidae), &c. 



ZOOGEOGRAPHICAL REGIONS 223 

The so-called American ostrich (genus Rhea), is charac- 
teristic, and is represented by several species. Among 
the negative characters we may note the absence of 
crows and ravens, which do not extend south of Guate- 
mala. As in Australia there are many parrots. Among 
the reptiles interesting forms are the rattlesnakes, the 
boas and anacondas, and the lizards of the family 
Iguanidae, while there is a large number of toads and 
frogs, especially tree-frogs (Hylidae). Among the fish 
the dipnoan called Lepidosiren is important. 

Finally we must consider the markedly peculiar 
Australian region. Here the higher or placental 
mammals are absent, with the exception of bats, a few 
rodents of the mouse section, the dingo or native dog 
of Australia, and the pig of New Guinea, which is 
probably an introduced animal. As already explained, 
the region further includes the only living monotremes, 
Ornithorhynchus being found in Australia and Tas- 
mania, Echidna in Australia, Tasmania, and New 
Guinea, and Proechidna in New Guinea only. 

The marsupials are extraordinarily numerous and 
very diverse, and a peculiar feature is that the more 
specialized forms, e.g. the certainly modern tree- 
kangaroos, occur towards the north, in Queensland and 
New Guinea, &c., whereas the more primitive forms, 
e.g. the Tasmanian wolf and Tasmanian devil, occur 
to the south, in the island of Tasmania. This is another 
link in the chain of evidence which suggests that 
Australia received its original marsupials from the 
south, through a connexion with South America, 
rather than from the north, through the islands of 
the Austro-Malayan region. We need not consider 
further the marsupials of the region beyond noticing 
that there are forms adapted to almost every kind of 



224 ZOOGEOGRAPHICAL REGIONS 

habitat, and showing curious adaptive resemblances 
to the placentals. An interesting form, discovered not 
many years ago, is the marsupial mole (Notoryctes), 
with a curiously close resemblance to the typical mole 
of the Old World. 

The birds of the region are interesting and peculiar. 
There are no true finches, no woodpeckers, no pheasants, 
and no vultures. New Guinea is especially remarkable 
for its beautiful birds of paradise, represented on the 
mainland chiefly by the bower-birds. Mound-turkeys 
and lyre-birds occur both on the mainland and in the 
islands, and the parrots are exceedingly numerous and 
very characteristic, while the related cockatoos are 
almost peculiar. New Zealand, with many peculiar 
birds, has some remarkable parrots, notably Nestor, 
which has become carnivorous, preying upon sheep, 
and the nocturnal owl parrot (Stringops) with a degene- 
rate keel on its sternum, and but little power of flight. 
Pigeons are also very abundant, and include the most 
brightly coloured members of the order. The honey- 
eaters (Meliphagidae) are peculiar to the region. 

Very striking also are the Running birds. New 
Zealand has the curious little Apteryx, as well as the 
extinct moa (Dinomis), Australia the emu and casso- 
wary. 

The reptilian fauna is less peculiar, but New Zealand 
has a very primitive lizard (Hatteria, p. 228) and no 
snakes. Queensland and New Guinea share with America 
an abundance of tree-frogs of the family Hylidae. The 
type genus Hyla occurs all over Australia, and the 
presence of many members of the family in the Austra- 
lian continent is the more remarkable in view of its 
complete absence from Africa and India (cf. p. 118). 

The fish fauna of the streams and lakes is somewhat 




m 



p 




Fig. 48. Lyre Birds with nest and eggs. 
{From a specimen in the Royal Scottish Museum.) 



ZOOGEOGRAPHICAL REGIONS 225 

poor, but the presence of the very primitive dipnoan 
fish Ceratodus is important. This fish, now found only 
in the rivers of Queensland, lived in the far-off Devonian 
period in the seas of the northern hemisphere, and is 
one of the curious rehcs of the AustraHan continent. 
Another is a mussel called Trigonia, now found only 
off Australian coasts, but once abundant in the Jurassic 
and Cretaceous seas of Europe. Still another curious 
relic is the mountain shrimp (Anaspides), a primitive 
type of crustacean found only in the mountain region 
of Tasmania, and apparently closely related to forms 
found fossil in Carboniferous and Permian beds in 
Europe and North America. These old-fashioned forms 
are perhaps in some respects even more striking than 
the marsupials in suggesting the long isolation of 
x4ustralia, and the extraordinary differences between 
its fauna and that of the rest of the world. 

Refebences. The following are the more important books on the 
subject of this chapter : Wallace, Geographical Distribution of Animals 
(London, 1876) ; Sclater, The Geography of Mammals (London, 1899) ; 
Lydecker, A Geographical History of Mammals (Cambridge, 1896) ; 
Beddard, A Text-book of Zoogeography (Cambridge, 1895) ; Trouessart, 
La Oiographie Zoologique (Paris, 1890) ; Heilprin, The Geographical 
and Geological Distribution of Animals (London, 1887) ; Arldt, Die 
Entvncklung der Kontinente und ihrer Lebewelt (Leipzig, 1907). See also 
Geoffrey Smith, A Naturalist in Tasmania (Oxford, 1909), for a dis- 
cussion of the origin of the Australian fauna. A very elaborate series of 
plates, with a considerable amount of text and a full bibliography, will 
be found in the Atlas of Zoogeography, by Bartholomew, Clarke & 
Grimshaw (Edinburgh, 1911). 



\ 



1404 



APPENDIX 

OUTLINE CLASSIFICATION OF ANIMALS 

Readers who are not well acquainted with modern zoology 
may find the following outline classification useful for refer- 
ence. Fuller details will be found in any of the zoological 
text-books, e.g. Thomson's Outlines of Zoology (Edinburgh), 
or the more systematic Natural Histories, e.g. The Royal 
Natural History (London). 

Of the terms used in modern classification, the word phylum 
is important. A phylum includes a group of animals 
whose members are characterized by a common ground-plan 
of structure, and are believed to have been descended from 
a common ancestor. Thus we distinguish the members of the 
'phylum of vertebrates from all the varied phyla of inverte- 
brates by the fact that all have at some period of life a dorsal 
supporting rod called the notochord, possess a tubular nervous 
system, and have their respiratory organs, whether lungs or 
gills, originating from the anterior end of the food-canal. 
This phylum is divided into a number of smaller units or 
classes as follows : 

PHYLUM VERTEBRATA. 

Class Mammalia, including warm-blooded hairy animals 
whose young are nourished by milk after birth, with three 
sub-classes : 

Sub-class I, Eutheria or Placentalia, the highest and most 
intelligent manmials, whose young are nourished before birth 
by an organ called the allantoic placenta, and are therefore 
born with the form of the adult ; including nine orders. 

1. Primates, including monkeys, apes and man, as well as 



APPENDIX 227 

the more primitive lemurs, forms with usually opposable 
thumb and great toe, mostly arboreal in habitat. 

2. Chiroptera, or bats, insect-eating or fruit-eating forms 
with the power of flight, the fore-limbs being greatly modified, 

3. Insectivores, generalized and usually small animals, with 
affinities both with primates and with marsupials, usually 
feeding on insects, and having cusped teeth. Examples : mole, 
shrew, hedgehog. 

4. Carnivora, or flesh-eaters, a large order of often powerful 
animals, with strong teeth, adapted either for life on land 
or in water, having four to five toes. Examples : cat, dog, 
bear, &c. 

5. Ungulata, herbivorous animals, often of large size, with 
a reduced number of toes, and teeth adapted for a vegetarian 
diet. In one sub-order (Perissodactyla) the third or middle 
toe tends to predominate, and may be the only one present, 
e. g. horse ; in the other sub-order ( Artiodactyla) the third and 
fourth toes are equally developed, e.g. sheep and cow. The 
elephant and the rock-conies (Hyrax) of Syria show certain 
primitive characters, absent in other ungulates. 

6. Rodentia, the gnawing animals, usually small, and having 
characteristic chisel-edged incisor teeth, by means of which 
they obtain their food. Rabbits, rats and mice are examples. 

7. Cetacea, or whales and dolphins, mammals very perfectly 
adapted for life in water. 

8. Sirenia, or sea-cows, an old-fashioned group, including 
only two living forms, also adapted for life in the water. 

9. Edentata, an old-fashioned heterogeneous order, including 
sloths, ant-eaters, armadillos, &c., all with relatively simple 
brains. 

Sub-class II, Metatheria or Marsupialia, including mammals 
whose young are born imperfectly developed, and are carried 
by the mother after birth in a pouch, or marsupium ; comprising 
two orders: 

1. Polyprotodontia, carnivorous forms, with numerous in- 
cisor teeth, including the opossums and the Tasmanian wolf. 

P 2 



228 OUTLINE CLASSIFICATION OF ANBL\LS 

2. Diprotodontia, herbivorous forms, with only two incisor 
teeth in the lower jaw, including kangaroos, the wombat, &c. 

Sub-class III, Prototheria, egg-laying primitive mammals, 
with one living order, Monotremata, which contains only three 
living kinds of mammals, the duck-mole (Ornithorhynchus), 
and the two spiny ant-eaters (Echidna and Proechidna). 

Class Aves or Birds, including warm-blooded forms 
clothed with feathers. The living forms may be divided into 
two divisions : 

1. Carinatae, or flying birds, with many orders, having a keel 
on the sternum, and usually the power of flight. 

2. Ratitae, or running birds, long-legged forms, with no keel 
on the sternum and rudimentary fore-limbs, including only 
a few living forms, e. g. the ostrich, cassowary, emu, &c. 

Class Reptilia or Reptiles, cold-blooded scaly animals 
with five living orders, and many extinct ones : 

1. Crocodilia or crocodiles and alligators. 

2. Chelonia or turtles and tortoises. 

3. Ofhidia or snakes. 

4. Lacertilia or lizards. 

5. RhyncJiocephalia, including only the New Zealand lizard 
called Hatteria, with many primitive characters. 

Class Amphibia or Amphibians, smooth-skinned forms with 
gills in the early stages, and lungs in the later, including forms 
like frogs and toads, without tails in adult life, and those like 
newts and salamanders, which keep the tail throughout life. 

Class Pisces or Fishes, permanently aquatic forms with 
gills and scales. The classification is a matter of difficulty, 
owing to the vast number of fossil forms. It is sufficient to 
note here that most living fishes are Teleosteans, forms with 
a completely bony skeleton and a swim-bladder used as hydro- 
static organ. Sharks and skates, &c., are Elasnwhranchs, and 
have a cartilaginous skeleton, the living forms being the 
specialized remnants of a large and primitive group. As 
Ganoids we may group a few living forms, very different from 
each other, but sharing with the Elasmobranchs certain primi- 



APPENDIX 229 

tive features, though they have a swim-bladder like the 
Teleosts. Such are sturgeons, bony pike, the polypterus of the 
Nile, and so forth. Finally, the Dipnoi or double-breathing 
fish include only three living forms (Ceratodus, Protopterus, 
and Lepidosiren), interesting because they possess both lungs 
and gills. 

The phylum vertebrata includes in addition some other 
small groups, such as the Cyclostomes or round-mouths (hag 
and lamprey), the Tuni gates or Sea-squirts, degenerate when 
adult, but almost tadpole-like when young, and so forth. 

Though we commonly use the term invertebrate as a con- 
venient contrast with vertebrate, there are many phyla of 
invertebrates not nearly related to each other. The highest 
is the PHYLUM MOLLUSCA, including forms breathing by 
gills, usually furnished with a limy shell, having a loose fold 
of skin called the mantle, and a muscular protrusion, on which, 
e.g., the snail creeps, called the foot. There are three important 
classes : 

1. The Cephalopoda or cuttles, marine forms in which the 
shell is usually lost, active and carnivorous in habit. 

2. Lamellibeanchiata or bivalves, forms like oyster and 
mussel, with a double shell, usually sedentary in habit. 

3. Gasteropoda or univalves, including snails, slugs, peri- 
winkle, &c., in which the shell is present or absent, and when 
present has but one valve. 

The very large PHYLUM AETHROPODA includes animals 
in which some at least of the segments of the body are fur- 
nished with jointed appendages. There are three main 
classes : 

1. The Crustacea, mostly aquatic forms, with a hard coat, 
two pairs of antennae, and gills, including large forms like crab 
and lobster, and the small copepods or water-fleas, &c. 

2. Antennata Tr ache ATA, including insects, millipedes, 
and centipedes, and the curious worm-like Peripatus, all 
breathing by air-tubes, and having one pair of feelers or 
antennae. Most live on land. 



230 OUTLINE CLASSIFICATION OF ANIMALS 

3. Arachnoidea, including spiders, scorpions, the king- 
crab, &c., as well as many parasites. They have no antennae, 
and the breathing organs are very diverse. 

The PHYLUM ECHINODEEMA includes a great number 
of marine animals, of radiate form, often with limy skeletons. 
The living classes comprise the sea-urchins (Echinoids), star- 
fish (Asteroids), brittle-stars (Ophiuroids), sea-cucumbers 
(Holothuroids), and sea-lilies (Crinoids). 

The Phylum of ANNELIDS includes all the different kinds 
of segmented worms, including both the sea-worms and the 
earthworms. Among worm-like types we have also many 
parasitic forms, of minor importance so far as distribution is 
concerned, and such free-living forms as Rotifers. 

The PHYLUM COELENTERA includes a great number of 
aquatic, usually marine, organisms, often of great beauty and 
of great diversity. Among them we have sea-firs and their 
allies, and the fresh-water hydra (Hydromedusae) ; the sea- 
anemones, corals, alcyonarians, large jellyfish and related 
forms, all of somewhat more complicated structure (ScY- 
phozoa) ; and finally those delicate iridescent bells which float in 
the open waters of the ocean, and constitute the Ctexophora, 
because of the delicate combs by means of which they swim. 
The sponges, all aquatic and mostly marine, constitute the 
PHYLUM PORIFERA, and the minute PROTOZOA, of great 
importance in that many parasitic forms are included, form 
a large phylum of very simple animals. 



INDEX 



Aard-wolf, 125. 
vark, 135, 219. 
Abysfal fauna of sea, 157, 

158, 169, 179-81, 206. 
of lakes, 197, 204-5. 
Abyssinia, &3, 84. 
Acacias, 129, 146. 
thorny, 122, 123. 
Acanthephyra, 178. 
Accentor, 5)0. 
Acorn shells, 160. 
Acipenser, 200. 
Acrobates, 112. 
Adansonia, 122. 
Addax, 128. 
Adelops, 207. 
Aelurus, 81. 
Aepvceros, 129. 
.Africa, 9, 11, 12, 32, 34, 40, 

56. 72, 80-3, 86, 98, 100-25, 

126-40, 145-52, 153, 182, 

200-24. 
Africa, Central, 188. 
Eiistern, 128, 12<), 130. 
North, 88, 128, 129, 133, 142, 

210. 

South, 55, 128, 129, 130. 
South-western, 98, 99, 102. 

106, 115, 118, 119, 128. 
tropical, 210. 
African lakes, 188. 
Agriophylluni, 68, 69. 
Agulhas, 170. 
Agutis, 110, 115. 
Alactaga, 65. 
Alashan, 69. 
Alaska, 22. 
Alca, 163. 
Alces, 40. 
Alcyonarians, 175. 
Alders, 19. 
AJepocephalus, 179. 
Algae, 158, 1,59, 163, 165, KiS, 

im, 172, 173. 
Alpine regions, 62. 
Alps, 49, 72, 74, 87. 88, 89, 90. 
Amazon, R., 110, 192. 
Aniblyopsis, 207. 
Aniblyrhynchus, 149. 
Amblystoma, 194, 19.5. 
America, 21, 40, 49, 62, 81, 

84, 106, 107, 110, 116, 117, 

132, 1.50, 15.3, 165, 201, 224. 
Central, 101, 106, 142, 147, 

214 ; see North America, 

South America. 
American continent, 211, 

214. 
Amoebae, 188. 



Amphibians, 90, 149, 151. 
166, 184, 194, 195, 206, 217. 
Aniphipods, .30. 
Amu Daria, 58, 59. 
Anabas, 119. 
Anaconda, 117, 223. 
Anaspides, 225. 
Andes Mts., 9, 80, 85, 87, 88, 

126, 210. 
Angola, 124, 133. 
Annelids, 167, 168, 175, 181. 
Anodon, 191. 
Anomaluridae, 109, 219. 
Antarctic area, 15, 21, 32, 
163. 

continent, 214. 
Ant-eaters, 13, 94, 111. 

banded, 1.39. 

hairy. 111. 

scaly. 111. 

two-toed, 111. 
Antechinoinvs, 139. 
Antelope, 11, 32, 40, 60, 7.5. 
80, a3, 84, 106, 123, 126, 127, 
128, 131, 132, 136, 139, 210, 
218. 

African sable, 107. 

harnessed, 107. 

pala, 129. 

saiga, 59. 

water-buck, 129. 130. 
Anthropoid apes, 98, 213, 

217. 
Antilocapra, 61. 
Ants, 119, 142. 

driver, 119. 
Apteryx, 224. 
Aphrodite, 168. 
Apes, 102. 

black, 217. 
Aquila, 88. 

Arabia, 86, 118, 128, 139. 
Aral, Sea of, 58. 
Arctic America,16,23,25,27. 

Asia, 2.3. 

Circle, .34, 50. 

fox, 23, 26. 

hare, 18, 20, 22, 88. 

regions, 22, 31, ;?2, 161. 

sea, 12. 

waters, 33. 

wolf, 21, 22. 
Arctictis, 106. 
Arctogaea, 213, 215. 
Arctogaeic realm, 215. 
Arctomys, 62, 86. 
Argali, 82. 

Argentine, 9, 55,64, 113, 123, 
132. 131, i:«. 



Argyropclecus, 178. 
Armadillos, 13, 134, 13.5. 
Artemia, 182, 205. 
Artemisia, 69. 
Arvicola, 87. 

Asia, 11, 12, 21, 22, 32. 38, 42, 
43, 47, 50, 51, 54, 5(), 58, 61, 
62, 82, 101, 107, 119, 129, 140, 
210, 215. 

Central, 52, 54, 82, 83, 8.5, 
89, 98. 

Northern, 46. 
South-eastern, 77, 98, !«. 
106-8, 115, 117. 
steppes of, :M, 52, i;i3, 136. 
tropical, 210. 
Asio, 147. 
Ass, 61. 

wild, 132, 1.^3, 218. 
Astacus, 200. 
Atlantic, 163, 178. 
Atlas Mts., 10, 80, 82, 126, 

132, 215. 
Ateles, 100. 
Auk, 24. 
great, 16.3. 
little, 163. 
Australia, 34, 55, 56, 102, 
103, 105, 114, 115, 121, i;i8- 
40, 153, 162, 191, 208, 209, 
213, 214, 215, 220-5. 
Eastern, 112. 
North, 112. 
South, 142. 
West, 112. 
Australian region, 135, 1,38, 

218. 
Austro - Malayan region , 

223. 
Axolotls, 195. 
Azores, 154. 

Babbling thrushes, 218. 
Babirusa, 107. 
Baboons, 98, 100, 124. 

African, 124. 

Arabian, 78. 

dog-faced, 213. 
Bactrian camel, 60. 
Badger, 44, 46, 216. 
Battln Land, 16. 
Bahamas. 173. 
Baikal, Lake, 182, 196, 204. 

seal, 182, 192, liXi. 
Balaena, Xi, 177. 
Balaenoptera, 3;^. 
Balaton, Lake, 199, 204. 
Bali, island of, 213. 
Baobab, 122. 



232 



INDEX 



Barnaclets, 160. 

Bath ypelagic animal;?,!'!, 

179, 180. 
Bathyscia, 207. 
Bats, 223. 

fox, 102. 

fruit, 102, 103. 217, 219. 

horse-shoe, 221. 

insect-eating, 217. 

^■aInpire, 103, 221. 
Bar of Biscay. 165. 
Bear. 44, 80, 106. 1-26. 222. 

black, 45, 80. 

brown. 45, 80. 

cat, 106. 

frizzly, 45, 80. 
[alayan, 106. 

parti- coloured, 81. 

sloth, 106. 

spectacled, 80. 
Beaver, 42, 43, 191, 193, 
Bees, 28. 
Beetles, 150, 207. 

water, 184. 
Belg^ium, 59, 151. 
Benguela current, 170. 
Bering Strait. 16, 82, 212. 
Bermudas, 154. 
Birds, 113, 146, 193, 216, 218, 
219, 222, 224. 

of paradise, 113, 224. 

rice, 147, 216. 
Bird cherry, 38. 
Bison, 61. 
Bithynia. 204. 
Bivalves. 167. 
Black Sea. 159, 180. 
Blessbok, 130. 
Boa, 117, 223. 

tree, 116. 
Bobac, 63, 65, 87. 
Bog moss. 19. 
Bolivia, 85, 134, 135. 
Bonasa, 47. 
Bonito. 177. 
Bontcbok, 1.30. 
Bonv pike, 185. 
Borneo, 98. 104, 155, 217. 
Bos, 61, 81. 127. 
Bower-birds. 224. 
Bradypus, 110. 
Brahmaputra. R., 192. 
Brazil, 9, 11, 110, 134. 
Brine-shrimps. 182.18.3,205. 
British Isles, 69, 151. 152. 

154. 
Brittle-star, 168, 184. 
Bubalis, i:». 
Buffalo, 127. 

short-horned, 127. 
Bufo, 90. 
Bulbuls. 218. 
Bull-frog, 49. 
Burma. 104. 117. 

Upper. 109. 
Buru, island of. 107. 
Bustards, 68, 69, 140. 
Butterflies. 28. 29, 119. 



L'accabis, 89. 
Cactus, 123, 146, 148, 179. 
Cactus wren, 141. 
Calainoicthvs, 220. 
California, 13, 141. 
Camel, 60, 61. 68, 85, 132. 
Campylorhyncbus, 141. 
Canachites, 47. 
Canada, 38, 40. 42. 147. 
Canadian lakes, 195. 
Canis. 23. 45, 67, 80, 126. 
Cape Colony, 125, 133. 
Cape of Good Hope, 170. 
Capercaillie. 47, 89. 
Capivara, 134. 
Capra, 75, 83. 
Capreolus, 41. 
Capuchin monkevs, 100. 
Cariacus, 40, 1.32. " 
Cariama, 142. 
Carinthia, 206. 
Carniola, 206. 
Carnivores, 38, 44, 67. 76. 79, 

81, 124, 162, 193. 209, 216, 

218, 219. 220, 221, 222. 
Carp, 217. 
Caspian Sea, 58, 182, 183, 

196. 
Cassowary, 140, 224. 
Castor. 42. 

Cat-fish, 199, 200. 203. 
Cats, 44, 67, 79. 105. 124. 

218. 
Cattle, 81. 

Caucasus, 63, 72. 83. 87. 
(.^ave faunas, 206. 
Cavy. 88, 134. 
Celebes, island of, 107, 

217. 
Cemas, 83. 
Cembra pine, 38. 47. 49, 

96. 
Centetes, 152. 
Centetidae, 220, -221. 
Central Europe, 31. 
Centrocercus, 69. 
Cephalophus. 107. 
Ceratodus, 118, 201, 225. 
Cercoleptes. 106. 
Cercopithecus. 99. 
Ccrthidea, 147. 
Cervulus, 107. 
Cervus, 40 ; see Deer. 
Cetacea, 162, 163, 192, 193. 
Ceylon. 115, 116, 218. 
Chameleon, 94, 113. 116, 

153, 221. 
Chamois, 84. 
Chatterei-s, 222. 
Chelone. 165. 
<'helonia, 165, 193. 
Cholydra, 193. 
Chenopodiaceae. 68. 
Chevrotains, 107, 110, 115, 

218, 219. 
water, 107. 
Chickaree, 42. 
Chili. 9. 85. 



C'himarrogale, 78. 
Chimpanzee, 98, 219. 
China, 58, 77, 78. 
Chinchilla. 87. 
Chipmunks. 42. 
Chirogale, 102. 
Chironomus, 206. 
Chiru, 84. 

Chlamydophorus, 134. 
Choloepus, 110. 
Chough. Alpine, 89. 
Chough-thrushes. K). 
Chrvsomitris, 89. 
Cichlidae, 203. 
Civets, 44, 102, 105, 152, 218, 
221. 

palm. 106. 
Cladonia, 19. 
Climbing perch. 119. 
Clouded leopard. 105. 
Coatis. 81, 106. 126. 
Cockatoos. 224. 
Cockles, 167. 
Cod, 161, 166. 
Coelentera, 168, 169, 18.5. 
Coelogenys, 88, 110. 
Coenolestes, 222. 
Colies, 220. 
Coliidae, 220, 
Colobus, 99. 
Colombia, 85. 
Condor. 88. 
Congo basin, 203. 

pygmies, 96. 
Connochoetes, 130. 
Conolophus. 148. 149. 
Continental Islands. 1.52. 
Continental Slope, 157. 
Conurinac, 222. 
Convoluta, 168. 
Corals, 181. 
Corixa, 206. 
Corsica, 82. 
Corvus, 27. 
Coryphaena, 177. 
Copepods, 174, 205. 
Covpu, 134. 
Crabs, 120. 167, 181, 205. 

liermit, 180. 
Cracidae, 222. 
Cranberries, 38. 
Crane. 141. 
Crayfish, 196, 200. 
Cre.sted cockatoos. 114. 
Cricetus, 66. 
Crinoids, 181. 
Crocidura. 220. 
Crocodiles, 115, 116, 194. 

196, 218. 
Crossbill, 47, 49. 
Crowberries, 19, 38. 
Crustacea, 158, 160, 167, 198. 

205, 207. 
Cryptobranchus, 91. 
Cryptoprocta, 152, 221. 
Ctenomys, IM. 
Ctenophora, 169. 
Curas-sows. 222. 



INDEX 



233 



CuiicwH, (59. 
Cuttles, 159, l(i(j, 170, 181. 
Cyclothone, 178. 
Cyuoiuys, 64. 
Cynopithecus, 217. 
Cystophora, ;w. 



Dabs, IWi. 
Dalmatia. 2(16. 
Danube, K.. 199. 
Darwin, 9, 115. 
Dasyprocta. 110. 
Dasypus, 1.35. 
Deer, .fi, 37, 40. 41, 75, 131, 
210, 216,218, 222; see Rein- 
deer, Roedeer. 

Asiatic, 106. 

pampa.s, 132. 

rod, 40, 42. 

Virginian, 40. 42. 
Delphinaptcrus, :ii. 
Demoiselle crane. 70. 
I )endrobatinae, 117. 
Dendrophis, 117. 
Deinnark, 199. 
Desert of Gobi. 58. (59. 
Desman, 79, 191, 196. 
Diatoms, 157. 
Didelphys, 113. 
Dingo, 223. 
Dinornis, 224. 
Dipnoi, 1&5. 201, 202, 214, 

220, 223, 225. 
Diprotodont marsupials, 

222. 
Dipus, 66. 
Dodo. 150. 
Dog, 106, 125, 219. 

Cape hunting, 12(5. 

Kskimo, '£i. 

Indian wild, 80. 
Dolichonyx, 147, 216. 
Dolphin, 159, 162, 177. 

blind, 192. 

ttsh-eating, 177. 

fresh-water. 192. l«(i. 
Dormouse, 37. 
Diuco, 9:1, 11(5, 218. 
Dryopliis, 117. 
Duck, 69. 
Duck-mole or Ornitho- 

rhynchus, 191, 2£i. 
Dugong, 1(52. 
Duikcrboks, 107, 130. 
Dzungarian Gate, 58. 



Eagle, Golden, 68. 

hawk, 88. 
Echidna, 223. 
Echinoderms, 168. 175, 178, 

181, 184. 
Ecuador, 8.5, 145. 
Edentates, 110, 1:54,218,219, 

222. 
Eel, 176, ISJ, 199. 

nmd, 195. 



Eider-duck. 24. 

Eland. 128. 

Elephant, 108, 109, 216. 218, 

219. 
Elk, 40. 41. 
EljTuus, (>4. 
Emu, 67, 140, 224. 
Emvs, ItM. 
England, 200. 
Equus, 59. 
Eremias, 70. 
p]rethizon, 43. 
Ermine, 23, 26, 46. 
Eryx, 70. 
Eskimo, 28. 
Ethiopian region, 215, 217, 

218. 
Euneccs, 117. 
Euphorbia, 122, 146. 
Eurasiatic continent, 40, 

49, 211. 
Europe, 13, 21, 50. 63, (58. 72, 

8:5, 84, 88, 89, 116, i;JO, 210, 

214, 225. 

(Central, 78, 194. 
Eastern, 200. 
Northern, 47. 
South, 89, 194. 
European Russia. 16. 
Exocoetus, 177. 



Falco, 27. 
Felidao. 218. 
Fells, 22, 44, 79. 
Fiber, 42. 
Fiji, 167. 
Finch, 147. 

citril, 189. 

snow, 89. 

Firth of Forth. 164. 186. 
Fish, 119, 120. 152, 178, UW, 
199, 223. 

cave, 207. 

deep-sea, 174, 178. 

flying, 177. 

fresh-water, 118. 151, 18:5, 
185, 200, 201. 203, 217, 224. 
Flies, 119, 206. 
Flycatchers, 217. 
Flying lemur, !«, 104, 217. 
Fox, 37, 44, 45, 80. 

Arctic, 23, 26. 

corsac, 67. 

long-eared, 126. 
F'ranz Josef Land, 16. 
Friendly Islands, 167. 
Frog, 90, m. 

ttshing, 166. 

flying, !«, 117. 

tree, 49, 118, 224. 
Fruit-pigeon, 115. 



Galago. 9:5, 102. 
Galapagos Islands, 145-51, 

16.5. 
Galeopithecu.s, 104, 217. 



Ganges, R., 189, 192, ISMi, 

218. 
Gannet. 16:5. 
Ganoids, 185, 192, 200, 202, 

220. 
Gastropods. 167, 175, 190. 
Gavialis, 218. 
Gazelle, 59. 84, 129. 
Gecinus, 47. 
Gecko, 70, 149. 
Geese. 69. 

Gemsbok, 128, 129, i:iO. 
Geospiza, 147. 
Gerfalcon, 27. 
Germany, (53. 
Gibbon, 98, 99, 217. 
Giraffe, 122, 129, 131, 136, i:J9, 

219. 
Glass crab, 176. 
Globigerina, 181. 
Glutton, 24, 44. 
Gnu, 1.30. 

Goat, 39. 40, 75, 76, 79, 83, 84, 
128, 146, 216. 

Arabian, wild, 8:3. 

Rocky Mts.. 84. 
Gobies, 160. 166, 199. 
(Golden mole, 219. 
Goniostoma, 178. 
Gopher, 62. 
(ioral, 83. 
Gorilla, 98, 219. 
Graculus, 89. 
Grasshopper, 71. 
Great Salt Lake, 182, 18:5, 

205. 
Greece, 71. 
Greenland, 16-29, :32. 
Grinnell Land, 22, 23. 
Grosbeak, 47. 
Grouse, black, 47. 

Canadian, 47. 

hazel, 47. 

Pallas's sand, (58, 69. 

red, 151. 

ruffed. 47. 

willow, 151. 
Grus, 70. 
Guanaco. 85. 
Gudgeon, 199. 
Guillemots, 24, 1(5:5. 
Guinea-fowl, 115. 
Gulf of Mexico, 55. 

Stream, 170. 
Gulo, 24. 46. 
Gypaetus, 88. 



Haddock, 166. 
Hairmoss, 19. 
Halicore, 162. 
Halobates, 176. 
Halolimnic fauna, 204. 
Hamster, 66. 
Hangnests, 216. 
Hare. American, 42. 
Arctic, 18, 20, 22, 88 ; .see 
also Polar hare. 



234 



INDEX 



Hare, jumping, VSi. 

mountain, 88. 

tailless. 66, 88. 
Hartebeests, 130. 
Hatteria, 213, 224. 
Hedgehog, tailless,152,219. 
Hemitragus, 83. 
Hermit crabs, 166. 180. 
Herpetodrvas, 117. 
Herring, 16(5, 182. 
Hesperomys, 146. 
Heterocephalus, 134. 
Hill-tits, 218. 
Himalayas, 10, 72, 76, 77. 

80-9, 210, 215. 
Hipfjopotamus, 219, 220. 
Hjort, 161, 171, 172, 174. 
Hoatzin, 115. 
Hog, river, 219, 220. 

wart. 219. 
Holarctic region, 215. 216. 
Honey creepei-s. 147. 
Honey eaters. 224. 
Horses. 60,61,65, 68. 108, 146. 

216, 219. 
Hubara, 68. 

Humming-birds. 220, 222. 
Hungary, 55, 58, 199. 
Hyaenas, 12.5, 126. 
Hydra, 191, 196, 
Hydrochoerus, 134. 
Hydromedusae, 189. 1S)0. 
Hydrophis, 165. 
Hvla, 224. 

Hylidae, 49, 118. -223, -224. 
Hyperodon, 176. 
Hypsiprymnodon, 1.36. 
Hyrax, 86, 219. 



Ibex, 8.3. 

Iceland, 16. 

Icteridae, 216. 

Ictonyx, 127. 

Iguana, 116, 149. 

India, 77, 80, 83, 100, 104-7, 

109, 111, 114, 115-19, 1,5.3. 
India, Further, 210, 213, 

215. 
Indian Ocean, 118, 148, 155, 

162, 165. 
Indies, West, 116, 221. 
Indo-Malayan region, 112, 

116. 
Indus, R., 192. 
Insectivores, 78, 79, 152, 191, 

193, 216, 217, 219, •22(t, -221. 
Insects, 119, 142. 
leaf, 1-20. 
Ireland, 151. 
Isopods, 207. 
lynx, 47. 



Jacamars, 114, 222. 
Jackal, 125. 
Jaguar, 105, 108. 



Japan. 1.5.5. 
Java, 155. 
Jays, 47, 49. 
Jellyfish. 169. 

fresh-water. 204. 20.5. 
Jerboa, 62, 64.65, 66, 124, 1.^3, 
im, 1.38. 

five-toed. 6.5. 
Jumping mouse. 62, 138. 
Jumping shrew, 124, 219. 
Jungle fowl. 11.5. 
Juniper, :j8. 



Kalahari desert. 123. 124. 

128, 129, 131. 
Kamchatka. 82. 
Kangaroo, 56, 6t. 65, 111, 
112, 123, i:J5-8, 208, 2l«, 
222. 

five-toed, 136. 

giant, l.'J6. 

rat, 136. 

tree. 111. 135. -22.3. 
Kansu, 78, 
Kea, 88. 

Khingan !Mts., 57. 
Kiang, 60, 85. 
Kilimanjaro, Sli. 
King Oscar Land, 16, 21, 22, 

2S. 
Kinkajou. 94, 106. 
Kirghiz, 59. 
Kittiwake. 24, 164. 
Kiwi, 140. 1,50. 
Klipspringer. 84. 12!). 130. 
Koala. 11.3. 

Koi'dofan desert, 122. 
Kudu, 128. 
Kuku \oi-. Lake. 77. 



Labrador. 16. 170. 
Lacerta, 90. 
Ladak, 79. 
Laemmergeier, 88. 
Lagidium. 87. 
Lagomys, 66. 
Lagopus, 20, 25, 151. 
Lagostomus, VM. 
Laminarian zone, 158. 
Langur, 77, 99; .sec also 
Semnopithecus. 

Himalayan, 78. 

Tibetan, 78, 80. 
Larch, Siberian, 38. 
Lark, Siberian. 69. 

steppe, 66. 
Leiotrichidae. 218. 
Lemming, 20, 22, 2:5, 27, m. 

Arctic, 87. 

Norwegian, 22. 
Lemur, 95, 101, 102, 152. 153. 

217, 219, 220, 221. 

flying, 93, 104, 217. 

mouse, 102. 

ring-tixiled, 102. 
Leopard, 105. 



Lepidosiren, 118. 201, 22:5. 
Leptocephalus, 176. 
Lcptonyehotes. 161. 
Lepus, 22, 88. 
Lerwa, 89. 
Leven. L., 197. 
Limnaea, 2ti4. 
Limnocnifla. 20.5. 
Limpet. 16ti. 
Linota. 2ii. 
Lion, 105, 125. 1-29. 
Lithocranius, 129. 
Littoral animals. 161. 167 
189. 

annelids, 168. 

area, 170. 

birds, 163. 

fauna, 196, 199. 

fishes, 166, 179. 
Lizard, 69, 90. 94. 116. 117 
142, 148. 153. 221, 222. 

flying. 218. 

marine, 149, 165. 
Llamas, 1*2, -222. 
Lobelias, 72. 
Lobodon, 162. 
Lobster. 167. 
Locusts, 71, 1-23. 
Loggerhead turtle. 165. 
Lombok. 213. 
Lophyrus. 5t\ 
Loxia, 49. 

Lumpsucker, 160, 166. 
Lung-fishes, 188. 
Lutraria, 167. 
Lycaon, 126, 219. 
Lynx, 37, 44, 78, 8<t. 
Lyre-birds, 224. 
Lyrurus, 47. 



Macacus, 77, 78, 216, 217. 

:Macaques, 78, 100. 
Tibetan, 78, 80. 

:Macaws. 114. 222. 

Mackenzie K., 21. 

Mackerel, 177. 

Macrorhinus, 162. 

Macroscelides, 124. 

Macrurus, 180. 

Madaga.scar, 101, 102, 105. 
117, 152, 153, 155, 208, 209, 
212, 213, 215, 217, 219, 22l>-2. 

Magpie, 49. 

Malagasj- region, 215, 220. 

Malay Archipelago. 212, 
214, 215. 

Peninsula, 102, 104, 109. 
region, 115, 153, 202, 217, 
222. 

Mammoth, 22. 

Manunoth Cave of Ken- 
tucky, 207. 

Manatee. 162, VSi, UK, 196. 

Manis, 111, 218. 

:Maral stag, 40. 

ilarkhor, 83. 

:Marmosets, 11, 101, 221. 



INDEX 



235 



Marmot, 46, 62, 86, 87. 

Alpine, 63, 87. 

Himalayan, 87. 

Prairie, 64. 

Kockv Mountain, 87. 
Marsupials, ,■>(). 123. 135, V.iS, 

•209, 214, 222, 223, 225. 
Marsupial mole, 224. 
Marten, 44, 45. 
Mediterranean, 10. 15.9, 165. 

170, 180. 
Medusa, 178. 
Medusoids, 190. 
Meerkat, 125. 
Melanocorvpha, 69. 
Meles, 46. 
Meliphagidae, 224. 
Melursus, 106. 
Mephitis, 44. 
Mesoiiekton, 177. 
Mosoplankton, 177. 
Mesopotamia, 139. 
Mexico. 43, 100, 110,194, 214. 
Mice, 146, 218. 
Mirhacl Sars Expedition, 

174, 177. 
Microchiroptera, 10.3. 
Micropus, 90. 
Minx, 44, 46. 
Mississippi, R., 55, 195. 
Moa, 224. 
Mole, 216. 
:\lolluscs. \m, 181, 184, 197, 

IDS, 204. 2U7. 
Moloch. 142. 
Mongolia, 41, 66, 82. 
Mongolian gazelle, 59. 
Mongoose, 12.5. 
Monkey, 11, 76, 77, 78, 93, 94, 
95, 97-100. 102, 105, 15:3, 209, 
219. 

broad-nosed, 100, 221. 

howling, 100. 

proboseis, 217. 

spider, 100. 

thumble.s.s, 93, 100. 
Monodon, .'IS. 
Monotreme, 191, 214. 
Montieola. 90. 
Montifringilla, 89. 
Morar, L., 197. 
Mosehus, 41, 8.5. 
Mosquitoes, 27, 28, 119. 
Motmots, 222. 
Mound turkeys, 224. 
Mountain ash", 38. 
Mountain shrimp, 225. 
Mt. Kenia, 72. 
Mouse, 221, 223. 
Mozambique, i:i3. 
Mudskippers, 118. 
Muntjaes, 107. 
Mus, 146. 

Muscieapidae, 217. 
Musk deer, 41, 85. 

ox, 17, 20, 21, 23, 81. 

shrew, 220. 
Musophagidae, 220. 



Musquash, 42. 

Mussel, 167, 191, 196, 197 

225. 
Mustela, 23, 45. 
Mya, 30, 167. 
Mycetes, 100. 
Myodes, 22. 
Myogale, 79. 
Myopotamus, 134. 
Myrmecobius, 139. 
Myrmecophaga, HI. 
Myriapods, 207. 
Mysis, 198, 199. 



Xansen, 18, 26. 

N'arwhal, 3.3. 

N'asalis, 217. 

Xasua, 81, 106. 

Xearctic .region, 215, 216, 

222. 
Xectarinidae, 220. 
Xeoturus, 195. 
Nekton, 176. 
Xemorhoedus, 83. 
Xeotropieal region, 216, 

221. 
Xereis, 168. 
Xestor, 88, 224. 
Xess, L., 197, 198. 
Xewfoiindland, 16. 
Xew Guinea, 9(j, HI, 113, 

208, 209, 214, 223, 224. 
Xew Siberian Islands, 16. 
Xewts. 195. 
Xew Zealand, 102, 140, 150, 

212, 214, 224. 
Xilgiri Hills, 83. 
Xisaetus, 88. 
Xoetiluca, 175. 
Xordenskiold, 17, 20, 31. 
X'^orth America, 11, 12, 13, 

.34, 38, 41-51, 56, 61, 64, 87, 

170, lft3, 194, 213, 215, 216, 

221, 222, 225. 
Xorth At]antic,163,176,212. 
Xorth Pacittc. 162. 
Xorth Sea, 157, 161. 
Xorthern Asia, 15, 25, 27. 
Xorthern Russia, 19. 
Norway, 72. 

Norwegian Sea, 161, 170. 
Notogaeic realm, 214, 215, 

216. 
Xotoryctes, 224. 
Nova iiembla, 16, 22, 27, 31. 
Xueifraga, 49. 
XutcracKers, 47, 49. 
Xyasa, L., 205. 
Nyctea, 27. 

Oceanic islands, 151. 
Okapi, 107, 219. 
Ommatoiihoca, 161. 
Opisthocomus, 11.5. 
Opossum, 9.j, 11.3, 213, 222. 
Orang, 98, 217. 
Orca, 34. 



Orcyteropus, 135, 219. 

Oreotragus, 84. 

Oriental region, 215, 216, 

217, 218, 220. 
Ornithorhynchus, 191, 223. 
Oryx, 128, 129. 
Ostrich, 67, 139, 140, 220, 223. 
Otaria, 161. 
Otis, 68. 
Otocyon, 219. 
Otter, 184, 191, 193, 19(5. 
Ounce, 79. 
Ovibos, 21. 
Ovis, 75, 82. 
Owl, 27, 147. 
Owl parrot, 224. 
Oxen, 128, 216, 218. 



Pacas, 88, 110. 

Pacific Ocean, 118, 145, 162, 

167. 
Palaearctic region, 216. 
Palaeotropical region, 217. 
Palalo worm, 167. 
Palms, 122. 
Pamirs, 57, 58. 
Pampas, 134. 
Panda, 81. 
Pangolins, 218, 219. 
Pantholops, 84. 
Papio, 124. 
Paradoxurus, 106. 
Paraguay, 132, 180. 
Parakeets, 114. 
Parrots, 94,114, 218, 220, 223, 

224. 
Partridge, 140. 

Greek, 89. 

snow, 89. 

wood, 115. 

Patagonia, 55, 85, 1.34. 
Peccaries, 107, 117. 
Pedetes, 133. 
Pedioecetes, 69. 
Pelagic animals, 1.57, 158, 

159, 161-7, 173-80, 198. 
Pelagic fish, 177. 

larvae, 167, 179. 

region, 170. 
Pelagothuria, 178. 
Polea, 84. 
Pelias, 90. 
Penguins, IKi. 
Perch, 199, 217. 
Periophthalmus, 118. 
Perisoreus, 49. 
Periwinkles, 167. 
Persia, 58. 
Persian gazelle, 59. 
Petauroides, 112. 
Petanrus, 112. 
Petrels, 24. 
Phyllirhoe, 175. 
Picas, 66, 67, 88. 
Piehieiago, 134. 
Pigeon, 224. 
Pig-footed bandicoot, 138. 



236 



INDEX 



Pigs, 107, 108, 146, 117, 218, 
219, 222, 223. 

bush, 107, 219. 

wUd, 107. 108. 
Pike, 199, 217. 
Pine grosbeak. 49. 
Pine-marten, 45. 
Pine saw-fly, 50. 
Pinicola, 49. 
Pipefish. 166. 
Pisidium, 198. 
Phacoehoerus. 107. 
Phalangers, 93, 94, 112, 113. 
136. 

flying, 112. 
Phascolarctos, 113. 
Pheasant, 68, 89, 115, 218. 
Philippine Islands,l(»4. 217. 

negritos. 96. 
Phoca, as, 192. 
Pholas, 167. 
Phrynocephalus, 69. 
Phrynosoma, 142. 
Phvllodaetylus, 149. 
Phyllornithidae, 218. 
Phvllostomatidae, KB. 
Physeter, 176. 
Phvtoplankton, 158, 173. 
Plaice, 166. 
Plankton, 174, 176, 177, 180, 

198. 
Planorbis. 204. 
Plantain-eaters, 114, 220. 
Planulae, 120. 
Platanista. 192. 
Plateaux. 73, 75, 78, 82. 
Plat j'rrhine monkeys, 100. 

221. 

Pleetrophenax, 26. 
Plovers, 67. 
Podoces, 69. 
Poecilogale, 127. 
Polar bear, 24, 32. 

hare, 42 ; see also Hare, 
Arctic. 
Polecat, 46. 127. 184. 
Polvchaete worms. 184, 

189, 190. 
Polynesia, 214. 
Polvpterus, 185, 202, 203. 

220. 
Polytrichum. 19. 
Pond snails, 184. 
Porcupine, 43. 

Canadian, 42, 110. 

tree, 43, 94. 110. 
Porpoises, 159, 177. 
Potamochoerus, 220. 
Potamogale, 219. 
Potorous, 136. 
Prairie-chicken, 69. 

-hen, 69. 

Prawns, 178, 184, 205. 
Prejevalski's horse, 59. 60. 
Primates, 76, 78, 94, 97, 124. 

219. 
Proechidna, 223. 
Prongbuck, 61. 



Proteles, 125. 
Proteus. 206. 

Protopterus, 118, 201,' 202. 
220. 

Protozoa. 170. 174. 198, 205. 
Ptarmigan. 19, 20. 23, 25, 

26. 27, 47, 89. 
Pteromys, 109. 
Pteropods, 177. 
Pudua. 85. 
Puflins, 163. 164. 
Puma, 44, 79, 105. 
Punjab, 82. 
Pycnodontidae, 218. 
Pygmv hippopotamus,153. 
Pyrenees, 63. 78, 87, 90. 
Pyrosoma. 175. 
Pythons, 116. 



Quagga, 132, 133. 
Queensland, 11. 112. 118. 
136, 201, 209. 223, 224, 



Raccoons, 81, 106. 126. 216, 

222. 
Rana, 49, 90. 
Rangifer, 21 ; see also 

Reindeer. 
Rat, 66. 

Rattlesnake, 223. 
Raven, 27. 

Realms, zoological, 212. 
Redpoll, 20. 
Red Sea, 170. 
Reindeer, 17, 20, 21. 26, 41. 
moss, 18. 
Reitbok, 129. 
Reptiles, 90. 115, 142, 147. 

150. 151, 164, 193, 196, 218, 

220 221, 223. 
Rhacophorus, 93. 117. 
Rhea, 67, 139, 223. 
Rhebok, 84, 129. 
Rhinoceros, 108, 1*2. 218. 

219. 
Rhinolophidae. 221. 
Rice-bii-d, 147. 216. 
River-hog, 153. 
Roach, 199. 
Rock conev, 86. 
Rock lobster, 176. 
Rock thrush, 90. 
Rocky Mountains, 44, 79, 

80 82 84 
Rodents, 38, 60, 64-7, 78. 

86, 89. 108, 110, 112, 124, 

125, 133-6, 152, 191, 193, 

216. 218, 219, 221-3. 
Roedeer, 41. 
Rorqual, 33. 
Rotifers, 184, 187, 198, 200. 

217. 
Running birds, 224. 
Rupicapra, 84. 
Russia, Southern. 55, 58. 



Russian Turkestan, 58. 
Ruwenzori. 72. 



S;\ge-brush. 69. 

cock, 69, 70. 
Sagitta, 175. 
Sahara, 68, 80, 106, 118, 121. 

126, 131, 215. 
Saiga antelope, 59. 84. 
Salamander. 90, 91, \M, 19.5. 
Salmon, 183, 217. 
Salpa, 175. 
Sambar. 107. 
Sandpiper, 24. 
Sand-rat. 134. 

-snake, 70. 

Sandwich Islands, 151. 
Sarcorhampus, 88. 
Sardinia, 82. 
Sai-gasso Sea, 159, 173. 
Saxicava, 30, 167. 
Sayansk divide, 41. 
Scandinavia, 16, 151. 
Scincus, 142. 
Sciuropterus, 42. 
Sciurus, 42. 
Scorpion, 120. 
Scotland, 72. 

lakes of, 197. 203, 204. 
Seals, 24. 30, 32, 33, 161, 163. 

182, 192. 
Seal, bearded. 33. 

crab-eating, 161. 

crested, 33. 

earless, 31. 

fur, 161, 163, 182. 

Greenland, 33. 

ringed, 33, 192. 

Rosss, 161. 

^^'eddelrs, 161. 
Sea-anemone, 169, 189. 

-butterfly, 175, 177. 

-cow. 162. 

-elephant, 162. 

-fir, 169. 189, 191. 

-horse, 166. 

-leopard, 162. 

-otter, 162. 

-pen. 169. 

-snake, 165. 

-squirt, 166. 

-urchin, 31, 168, 181, 184. 
Sebastes, 178. 
Sechwan, 78. 
Secretary bird, 140, 141. 

142. 

Selvas, 222. 

Semnopithecus. 77, 216,217. 
Senecios, 72. 
Seriemas, 141, 142. 
Serow, 83. 84. 
Serpentarius, 140. 
Serpula, 168. 

Sheep, 39, 40, 75, 76, 79, 80. 
82, 89, 128, 137, 216. 

Barbary, 82. 

Bighorn, 82. 



INDEX 



237 



Slu'll-fi.sh, l(i<). 
Shrews, lo'J, 221. 

Alpine, 78. 

flvmg, 112. 

Himalavaii swimming. 
78. 

.jumping, 124. 219. 

nmsk, 220. 

Tibetan mole, 79. 

tree, 104, lai. 218. 

water. 191, 19:5. 
Siberia, 13, 16, 44. 4.). 4fi. 49. 

(»), 8.5. 
.Siberian fir, .'$8. 
Silurus, 199. 
Sind. 82. 
Siren, 19.5. 
Sirenia, 1(52. 192, 1!W. 
.Sirex. .tO. 
Skate, im. 
Skink, 142. 
Skua, 24. 

Skunk, 44, 127. 21(5, 222. 
Sloth. 11, i:{, as, 95, 110. 
111. 

ground, 208. 

Snail, fresh-water, 190. 197. 
Snake, 116, 148. 149, 1;).{. 

grass, 194. 

sea, 16.5. - 

tree, 117. 

whip, 117. 

wood, 117. 
Snipe. 69. 
.Snow-bunting. 19, 26. 

-cock, 89. 
Snowy owl, 27 
Solenodon, 221. 
Solitaire, 1.50. 
Sonialiland, 1-2.5, VU. 
Sorex, 78. 

South America, 9, 12, .34, 
43, 5.5, 56, 80, 85. 87, 88, 93, 
101. 106, 108, 111, li:j-23, 
130-4, 13&-47, 149, 1.5:i, 192, 
202, 208, 209, 214, 21.5. 220. 
221, 222, 22:}. 
Southern England, .5ft. 

France. 59, 

hemisphere, 1.5. 
Spain, 7.3, 116. 
•Spermophilus, 62. 
.Sphagnum, 19. 
Spi<lers, 120, 207. 
Spitsbergen, 16, 21, -22, 2:1 

2.5. 27. 
Sponges, 16J1, 174, 175, 180, 
181, 18,5. 

fresh-water, 20.5. 
Spotted cuscus, 112. 
Springbok, 12J). 
Spur-rowl, 115. 
Squirrel, 13, 37, 42, 43, 62, 
10.5, 108, 218. 

flying, 42. 4.3, m, 104, 108, 
109, 112, 219. 

pygmy flying, 112. 

sugar, 112. 



Starfish, 31. 
Starling, 216. 
Stcinbok, 129. 
Stcnorhvnchus. 162. 
Sterlet, 200. 
Stickleback, 217. 
Stoat, 26, 44. 
Strepsiceros, 12S. 
Strepsiptera, 28. 
Stringops, 224. 
Struthio, im. 
Sturgeon, 185, 2(M). 
Sudan, 121, 124. 
Sumatra, 98, 217. 
Sun-birds, 220. 
Sunflsh, 174. 
Suricata, 125. 
Sus, 39, 219. 
Suslik, 62. 
Sverdrup Expedition. 16, 

18, 21, 2(!. 
Swift, Alpine, 90. 
Switzerland, 6.3, 74. 
Syntheres, 110. 
Syr Daria, 58. 
Syria, 86, 1.30, i:«). 
Syrrhaptes, 68, 



Tahr, 83. 

Tailless hedgehog. 1.52. 219. 

Takin, &i. 

Talpa, 216. 

Tamias, 42. 

Tanagers, 222. 

Tanganyika. Lake. 182, 

200-5. 
Tapir, 85. 108, 218. 220, 222. 
Tardigrada. 198. 
Tarim basin, 58. 
Tarsier, 102. 
Tai-sipes, 112. 
Tarsius, 102, 217. 
Tasmania, 102, 214. 
Tasnifinian devil, 223. 
wolf, 22:}. 
Taxidea, 46. 
Tench, 199. 
Tenrec, 219, 220. 
TeratoscincuH, 70. 
Terebella, 168. 
Termites, 120, 125, 1.35, 142. 
Terns, 24. 
Tetrao, 47. 
Tctraogallus, 89. 
Tetrastes, 47. 
Texas, 141, 296. 
Thalassochelys, 16.5. 
Thynnus, 177. 
Tibet, 57, 7.3, 74, 77, 80-4, 

87-9. 
Tichodroma, 89. 
Ticks, 120, i:30. 
Tiger. 44, 67, 105, 218. 
Timelidac, 218. 
Tinamus, 110, 222. 
Tipula, 206. 
Titanethes. 207. 



Toad, 90, 223. 

horned, 142. 
Tomopteris, 175. 
Tortoise, 165. 

giant, 147, 148. 1.50. 1.54. 

pond, 194. 

water. 184, 1!M5. 
Toucans, 114, 222. 
Tragelaphus. 107, 128. 
Tragulus, 107. 
Tree-creeper, 37. 

-frog, .37, 49, 22.3, 224. 

-heath, 72. 

-shrew, 104, 105, 218. 
Trichechus, 32. 
Trigonia, 225. 
Trigonocephalus, 71. 
Trimeresurus, 117. 
Trochospheres, 190. 
Tropidonotus, 194. 
Tropidurus. 149. 
Trypanosoines, 131. 
Tsetse flies, 119, i:», 131. 
Tucotucos, 1.34. 
Tunicates, 175. 
Tupaia, 104, 218. 
Turbot, 166. 
Turkestan, 70. 
Turtle, 164. 

American snapping. 193. 

green. 165. 

hawksbill, 16.5. 

leathery, 165. 

loggerhead, Ifio. 

marine, 193, 194. 
Tympanuchus. 69. 
Typhlomolge, 206. 
Tyrant shrikes, 217. 
Tyrol, 89. 

Ungulates, 3.5, .56, 60, 61, 65, 
75, 76, 81, 84, 86, 89, 97, 106, 
108, 110, 123, 127, 130, 131, 
1.33, 136, 137, 152, 153, 213, 
218, 219, 222. 

Unio, 204. 

United States, 55, 113, 142, 
147, 195, 214. 

Upper Egypt, 8.3. 

Uropsilus, 79. 

Ursus, 24, 45, 80, 106. 

"Victoria, 112. 
Victoria Land, 187. 
Vicuna, 85. 
Viper, 90. 
tree, 117. 
Viscacha, 64, i:U. 
Viverridae, 105. 
Voles, 87. 
Vultures, 76. 

Wallabies, 123, 1.35. 
Wallace, 146, 147, 150, 151, 

152 154. 
Wallace's line, 213. 



238 



INDEX 



Wall-creeper. 89. 
Walrus, 24, 30, 31, 32. 101. 

162. 
Wapiti. 39. 40. 42. 
Wart-hogs. 107. 
Water bears, 198. 

beetles, 197. 

boatmen, 197, 206. 

chevrotain, 107. 

fleas, 167, 198. 

mites, 184, 198. 

shrew, 191, 163. 

spider, 184. 

vole, 191, 193. 
Weasel, 44, 46, 127, 219. 



Welwitschia, 124. 

West Indies, 147. 152, 214, 

221. 
Whales, 31, 159, 162. 

bottle-nose. 176. 

Greenland. 33. 

killer, 32, 34. 

sperm, 176. 

whalebone. 30, 162, 176. 

white, 34. 
Whelks. 167. 
Whortleberries, 20, 38. 
Wild cat, 44. 

boar. 39. 

dog, 44. 



Willows, 19. 
Wolf, 23, 37, 44, 45. 
Wolverene, 46. 
Woodpeckers, 37, 47, 109, 
113. 

green, 47. 

spotted, 47. 

three-toed, 48. 
Wood wasp, 50. 
Wryneck, 47. 

Yak, 81, 82. 

Zebra, 60, 132, l.%3. 



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