CHAP. VI.

Of the Distribution of Animals.

1962. The geographical distribution of each species of animal, Dr. Fleming observes, may be represented by a circle, towards the centre of which, existence may be comfortably maintained; but as we approach the circumference, restraints multiply, and life at last becomes impracticable. Each species has a range peculiar to itself, so that the circle of different species intersect one another in every possible relation. Hitherto the geographical limits of but few species have been satisfactorily determined. These chiefly belong to the larger species of quadrupeds, as the African and Asiatic elephants, the ass and the quagga, the lion, hippopotamus, and polar bear. In the tribes of the less perfect animals, the species of which have been investigated by few, the extent of their geographical distribution has been very imperfectly determined. They appear to be limited to circumstances connected with temperature, food, situation, and foes.

1963. The degree of heat at the equatorial regions appears to be most favorable for the increase of living beings, and they diminish in numbers as we approach the poles. There is no latitude, however, which the perseverance of man has yet reached, where living beings have not been observed. The icy shores of the arctic regions are peopled as well as the arid plains or shaded forests of tropical climates. When, however, an inhabitant of the colder regions is transported to a warmer district, the increased temperature is painful, the functions become deranged, and disease and death ensue. The inhabitants of the warmer regions, when transported to the colder districts, experience inconvenience from the change of temperature, equally hurtful to the system, and fatal to its continuance. The polar bear appears to be accommodated to live in a region, whose mean annual temperature is below the freezing point. In those districts where the individuals of a species are most vigorous and prolific, the temperature most suitable for existence prevails. The native country for the horse is probably Arabia. There he exists in a wild state in the greatest numbers. In the Zetland Islands, where he is nearly in a state of nature, he is approaching the polar limits of his distribution. He has become a dwarf. He does not reach maturity until his fourth year, seldom continues in vigor beyond his twelfth, and the female is never pregnant above once in two years. At the line, where the energies of the horse terminate, however, the reindeer becomes a useful substitute. Its equatorial limits do not reach the shores of the Baltic.

1964. To compensate the variations of the seasons a variety of changes take place in the circumstances of animals. The clothing of animals, living in cold countries, is not only different from that of the animals of warm regions in its quantity, but in its arrangement. If we examine the covering of swine of warm countries, we find it consisting of bristles or hair of the same form and texture; while the same animals which live in colder districts, possess not only common bristles or strong hair, but a fine frizzled wool next the skin, over which the long hairs project. Between the swine of the south of England, and Scottish Highlands, such differences may be observed. Similar appearances present themselves among the sheep of warm and cold countries. The fleece of those of England consists entirely of wool; while the sheep of Zetland and Iceland possess a fleece, containing, besides the wool, a number of long hairs, which give to it, when on the back of the animal, the appearance of being very coarse. means of this arrangement, in reference to the quantity of clothing, individuals of the same species can maintain life comfortably in climates which differ considerably in their average annual temperature.

By

1965. The process of casting the hair takes place at different seasons, according to the constitution of the animal with respect to heat. The mole has, in general, finished this operation before the end of May. The fleece of the sheep, when suffered to fall, is seldom cast before the end of June. In the northern islands of Scotland, where the shears are never used, the inhabitants watch the time when the fleece is ready to fall, and pull it off with their fingers. The long hairs, which likewise form a part of the covering, remain for several weeks, as they are not ripe for casting at the same time with the fine wool.

1966. The moulting of birds is another preparation for winter, which is analogous to the casting of the hair in quadrupeds.

1967. The distribution of color in the animal kingdom, appears to be connected with the latitude as correlative with temperature. In the warmer districts of the earth, the colors of man, quadrupeds, and birds, exhibit greater variety, and are deeper and brighter, than in the natives of colder countries. Among the inhabitants of the temperate and cold regions there are many species which, in reference to the color of their dress, do not appear to be influenced by the vicissitudes of the seasons. In others, a very marked difference prevails between the color of their summer and winter garb.

A few

of the more obvious instances of these changes, in British species, may be here produced.

1968. The alpine hare is a very remarkable example. Its summer dress on the Grampian mountains is a tawney grey; but in winter it is a snowy white. The hair of the ermine is of a pale reddish brown during summer; in harvest it becomes clouded with pale yellow; and in November is of a snow-white color. There are many examples of changes in the color of the clothing in the feathered tribe. The white grous or ptarmigan is of an ash color in summer, and fine white in winter. The black guillemot (Uria grylle) is of a sooty black during summer; during winter its plumage is clouded with ash colored spots on a white ground. This change of color in the dress of animals seems intended to regulate their temperature by the radiation or absorption of caloric: a black animal will give out its heat by radiation much slower than one in a white clothing.

1969. The migration of animals is another circumstance affecting their distribution. Quadrupeds make only partial migrations; as the stag and the roe from the mountains to the plains. The winged and finned quadrupeds migrate more extensively, as the great bat_which inhabits England during summer, and spends its winters in a torpid state in Italy and the Greenland seal, which migrates southwards to Ireland in winter.

1970. The migrations of the feathered tribe are the most numerous; but the same species which is migratory in one country, is in some cases stationary in another; as the linnet, which is migratory in Greenland, but stationary in Britain. Migrating birds are either summer birds of passage, which arrive in this country in spring; or winter birds of passage, which arrive in autumn and depart in spring.

1971. The summer birds of passage are, among water birds, the terns and gulls; among land birds, the swallow, quail, turtle dove, &c. The winter birds of passage chiefly belong to the tribe of water fowls. The swallow, about whose migrations so many idle stories have been propagated and believed, departs from Scotland about the end of September, and from England about the middle of October. In the latter month M. Adanson observed them on the shores of Africa after their migrations from Europe. He informs us, however, that they do not build their nests in that country, but only come to spend the winter. M. Prelong has not only confirmed the observations of Adanson, in reference to swallows, but has stated, at the same time, that the yellow and grey wag-tails visit Senegal at the beginning of winter. The former (Motacilla flava) is well known as one of our summer visitants. The nightingale departs from England about the beginning of October, and from the other parts of Europe about the same period. During the winter season it is found in abundance in Lower Egypt, among the thickest coverts, in different parts of the Delta.Those birds do not breed in that country, and to the inhabitants are merely winter birds of passage. They arrive in autumn and depart in spring, and at the time of migration are plentiful in the islands of the Archipelago. The quail is another of our summer guests, which has been traced in Africa. A few, indeed, brave the winters of England, and in Portugal they appear to be stationary. But in general they leave this country in autumn, and return in spring. They migrate about the same time from the eastern parts of the continent of Europe, and visit and re-visit in their migrations the shores of the Mediterranean, Sicily, and the islands of the Archipelago. While these birds perform those extensive migrations which we have here mentioned, others are contented with shorter journeys. Thus the razor-billed auk (Alca torda), and the puffin (Alca arctica), frequent the coast of Andalusia during the winter season, and return to us in the spring.

1972. Our summer birds of passage, thus appear to come to us from southern countries, and, after remaining during the warm season, return again to milder regions. A few of our summer visitants may winter in Spain or Portugal; but it appears that in general they migrate to Africa, that unexplored country possessing every variety of surface, and consequently great diversity of climate. It is true that we are unacquainted with the winter retreats of many of our summer birds of passage, particularly of small birds; but as these arrive and depart under similar circumstances with those whose migrations are ascertained, and as the operations which they perform during their residence with us are also similar, we have a right to conclude that they are subject to the same laws, and execute the same movements. What gives weight to this opinion, is the absence of all proof of a summer bird of passage retiring to the north during the winter season.

The

1973. In proof of the accuracy of the preceding conclusion, we may observe that it is a fact generally acknowledged, that the summer birds of passage visit the southern parts of the country a few days, or even weeks, before they make their appearance in the northern districts. Thus, the common swallow (Hirundo rustica,) appears in Sussex about the beginning of the third week of April; while in the neighborhood of Edinburgh it is seldom seen before the first of May. The cuckoo appears in the same district about the last week of April; in Edinburgh seldom before the second week of May. reverse of this holds true with these summer visitants at their departure. Thus dotterells (Charadrius morinellus) forsake the Grampians about the beginning of August, and Scotland by the end of that month; while they return to England in September, and remain there even until November. A difference of nearly a month takes place between the departure of the goatsucker (Caprimulgus Europæus) from Scotland and from the south of England.

1974. The torpidity or hybernation of animals, is evidently designed to afford protection against the cold of winter. There are several quadrupeds which become torpid, as the bat, hedgehog, marmot, hamster, dormouse, &c. The torpid animals of Britain usually retire in October, and re-appear in April. Previous to their entrance into this state of lethargy, these animals select a proper place, in general assume a particular position, and even in some cases provide a small stock of food.

1975. All the torpid animals retire to a place of safety, where, at a distance from their enemies, and protected as much as possible from the vicissitudes of temperatures, they may sleep out, undisturbed, the destined period of their slumbers. The bat retires to the roof of gloomy caves, or to the old chimneys of uninhabited castles. The hedgehog wraps itself up in those leaves of which it composes its nest, and remains at the bottom of the hedge, or under the covert of the furze, which screened it, during summer, from the scorching sun or the passing storm. The marmot and the hamster retire to their subterranean retreats, and when they feel the first approach of the torpid state, shut the passages to their habitations in such a manner, that it is more casy to dig up the earth any where else, than in such

parts which they have thus fortified. Having thus made choice of situations where they are protected from sudden alterations of temperature, and having assumed a position similar to that of their ordinary repose, these hybernating animals fall into a state of insensibility to external objects. In this torpid state they suffer a diminution of temperature; their respiration and circulation become languid; their irritability decreases in energy; and they suffer a loss of weight.

1976. The abundance or scarcity of food has a powerful influence on the geographical distribution of animals. Many species of insects are restricted in their eating to one kind of plants, or are parasitical on one species of animal. The distribution of such animals is thus dependent on their food. The same remark is generally applicable to carnivorous and phytivorous animals. But, in many species, though the restriction is absolute as to the nature of the food, it admits of a considerable range with regard to the variety or kind. Thus, though the lion is restricted to flesh, his cravings are equally satisfied with the carcase of a horse, a cow, or even of man. The hog in general feeds on roots, but it is not confined to those of one kind of plant; hence it can subsist whereever the earth is clothed with verdure.

1977. The seasons exercise a powerful influence on animals, directly, in reference to their temperature, and, indirectly, with regard to the production of their food. Thus, the insect that feeds on the leaves of a particular tree, can only enjoy its repast during that part of the season when this tree is in leaf. How, then, is life preserved during the remaining portion of the year? The resources are numerous. It either exists in the

form of an unhatched egg, an inactive pupa, in the imago state, requiring little food, or actually becoming torpid.

1978. The birds which feed on insects in summer, in this climate, are, from the absence of this kind of sustenance in winter, obliged to have recourse to various kinds of vegetable food during that season. Should this change of diet be unsuitable, migration to other districts, where a proper supply can be obtained, becomes indispensably requisite. In compliance with these regulations, we observe numerous mammalia, birds, and fishes, accompany the shoals of herrings in their journeys; and the grampus and seal enter the mouths of rivers in pursuit of the salmon. The bats, which feed on insects in summer, could not in this country obtain a suitable supply of food. Yet the race is preserved, since the fall of temperature, which is destructive to insect life, brings on the winter torpor. With many quadrupeds, however, and even insects, especially the bee, where migration to more fertile districts is impracticable, and where torpidity is not congenial to the constitution, there is an instinctive disposition to be provident of futurity. Of quadrupeds which possess this disposition, the beaver and the squirrel may be considered as among the most remarkable.

1979. The influence of situation on the distribution of animals, is considerable. Some animals reside wholly in water; others are amphibious. Among terrestrial animals, there are many which execute all the operations of life in one particular situation, influenced, however by its various conditions. Such animals are necessarily limited to those countries where such situations occur. There are others, however, which shift their situations at particular seasons, without reference either to temperature or food. The curlew, which can at all times procure a subsistence on the sea-shore, and resist or counteract the changes of the seasons, retires during the period of breeding, to the inland marshes. The heron, which is equally successful in procuring food on the shore, is destined to build its nest on trees, and consequently must betake itself to wooded districts for the purposes of incubation. Its haunts in Britain are termed heronries or heronshaws. Many terrestrial animals, especially of the insect kind, pass the first period of their existence in the water. The old animals in consequence seek after that element in which to deposit their eggs, however independent they may be of its presence for their ordinary personal wants.

1980. The rapacity of some animals considerably affects the distribution and extension of others. Of all the foes of the animal tribe none is so powerful as man. Against many species, hostile to his interests, he carries on a war of extermination. Others he pursues for pleasure, or for the necessaries or luxuries of life which they yield. In these conquests, the superiority of his mental powers is conspicuously displayed, and his claim to dominion established. Unable to contend with many species in physical strength, he has devised the pit-fall and the snare, the lance, the arrow, and fire arms. Aided by these, every animal on the globe must yield to his attempts to capture. The lion, the elephant, and the whale, fall the victims of his skill, as well as the mouse or the sparrow. Since the use of gunpowder, indeed, the contest is so unequal, that it is in the power of man to control the limits of almost every species whose stations are accessible. The havoc which man thus commits in the animal kingdom has occasioned the extirpation of many species from those countries of which they were formerly the natural possessors. In this island, since the Roman invasion, some species of quadrupeds and birds have disappeared; and others are becoming every year less numerous. those which have been extirpated, the bear and the beaver, the crane and the capercailzie, may be quoted as well known examples. The same changes are taking place in every cultivated region of the earth, each having within the very limited period of history or tradition, lost many of the original inhabitants.

Of

1991. An acquaintance with the laws which regulate the geographical distribution of animals is indispensably necessary in our attempts to naturalise exotic species. The temperature most suited to their health, the food most congenial to their taste, and best fitted to their digestive organs, the situation to which their locomotive powers are best adapted, -and the foes against which it is most necessary to

guard them, are circumstances on which we ought to bestow the most scrupulous attention, in order to insure success. There are many animals which can call forth but few counteracting energies, and, consequently, cease to thrive, upon the slightest alteration taking place in their physical condition. With others, the case is very different, and these we can easily naturalise. They can accommodate themselves to a variety of new conditions, and successfully resist the destructive tendency of the changes to which we subject them.

1982. The change in the condition of the animals we wish to naturalise, should, in all cases, be brought about as slowly as circumstances may permit. In this manner, the first counteracting effects of the system grow into organical habits, before all the evils of the situation are experienced, in which they are destined ultimately to reside. In this gradual manner, man has become fitted to reside in every climate, as well as many of the animals which he has reclaimed.

1983. The total number of species of animals hitherto described exceeds fifty thousand; but of these, upwards of forty thousand are insects or reptiles.

1984. The British Fauna, or number of species of animals, native or naturalised in Great Britain, might be arranged as residents, periodical visitants, irregular visitants extirpated, extinct and naturalised animals. But, as Dr. Fleming has observed, British zoologists have paid little or no attention to the geographical distribution of the native animals. Species which really live in the country are associated with such as visit it periodically, and with those which have been extirpated, have become extinct, or have been naturalised. The consequence is, that it is difficult to form a correct view of either the number or characters of our native animals.

CHAP. VII.

Of the Economical Uses of Animals.

1985. On the importance of animals in the arts as laborers, as furnishing food, clothing, medicine, and materials for various manufactures, it is needless to enlarge.

1986. As laborers the quadrupeds are almost solely employed; and of these the most universally useful is the horse, and next the ox and the ass. Without the constant use of these animals, the general economy of civilised life in the temperate climates, and more or less in every climate, would be entirely altered; as would be the economy of Arabia, and many parts of Africa without the use of the camel. The dog is valuable as a messenger and watching animal, and has been and is employed in that capacity in all ages and countries.

1987. As articles of food man employs animals belonging to every class, from the quadruped to the zoophyte. In some cases, he makes choice of a part only of an animal, in other cases, he devours the whole. He kills and dresses some animals, while he swallows others in a live state. The taste of man exhibits still more remarkable differences of a rational kind. The animals which are eagerly sought after by one tribe, are neglected or despised by another. Even those which are prized by the same tribe in one age, are rejected by their descendants in another. Thus the seals and porpoises, which, a few centuries ago, were eaten in Britain, and were presented at the feasts of kings, are now rejected by the poorest of the people.

1988. Those quadrupeds and birds which feed on grass or grain, are generally preferred by man to those which subsist on flesh or fish. Even in the same animal, the flesh is not always of the same color and flavor, when compelled to subsist on different kinds of food. The feeding of black cattle with barley straw, has always the effect of giving to their fat a yellow color. Ducks fed on grain have flesh very different in flavor from those which feed on fish. The particular odor of the fat of some animals seems to pass into the system unchanged, and, by its presence, furnishes us with an indication of the food which has been used.

1989. While many kinds of animals are rejected as useless, there are others which are carefully avoided as poisonous. Among quadrupeds and birds, none of these are to be found, while, among fishes and mollusca, several species are to be met with, some of which are always deleterious to the human constitution, while others are hurtful only at particular seasons.

1990. The use of skins as articles of dress, is nearly coeval with our race. With the progress of civilisation, the fur itself is used, or the feathers, after having been subjected to a variety of tedious and frequently complicated processes. Besides the hair of quad

rupeds, and the feathers of birds used as clothing, a variety of products of the animal kingdom, as bone, shells, pearls, and corals, are employed as ornaments of dress, in all countries, however different in their degree of civilisation.

1991. Medicine. The more efficient products of the mineral kingdom have in the progress of the medical art in a great measure superseded the milder remedies furnished by animals and vegetables. The blister-fly, however, still remains without a rival; and the leech is often resorted to, when the lancet can be of no avail.

1992. The arts. The increase of the wants of civilised life calls for fresh exertions to supply them, and the animal kingdom still continues to furnish a copious source of materials for the arts. Each class presents its own peculiar offering, and the stores which yet remain to be investigated, appear inexhaustible.

CHAP. VIII.

Principles of improving the Domestic Animals used in Agriculture.

1993. The animals in use in British agriculture are few, and chiefly the horse, ox, sheep, swine, and domestic fowls. The first is used solely as a laboring animal, and the rest chiefly as furnishing food. In applying the general principles of physiology to these animals with a view to their improvement for the use of man, we shall consider in succession the principles of breeding, rearing, and feeding.

SECT. I. Of improving the Breed of Animals.

pro

1994. By improvement of a breed is to be understood the producing such an alteration in shape or description, as shall render the animal better fitted for the labors he has to perform; better fitted for becoming fat; or for producing milk, wool, eggs, feathers, or particular qualities of these. The fundamental principle of this amelioration is the per selection of parents. Two theories have obtained notice on this subject, the one in favor of breeding from individuals of the same parentage, called the in-und-in system, and the other in favor of breeding from individuals of two different offsprings, called the system of cross breeding. As is usual in such cases, neither theory is exclusively correct, at least as far as respects agricultural improvement; for, as will afterwards appear, the principles on which a selection for breeding so as to improve the carcase of the animal depends, will lead occasionally to either mode.

1995. That the breed of animals is improved by the largest males, is a very general opinion; but this opinion is the reverse of the truth, and has done considerable mischief. The great object of breeding, by whatever mode, is the improvement of form, and experience has proved that crossing has only succeeded in an eminent degree, in those instances in which the females were larger than in the usual proportion of females to males; and that it has generally failed where the males were disproportionally large. (Culley's Introduction, &c.) The following epitome of the science of breeding, is by the late eminent surgeon, Henry Cline, who practised it extensively on his own farm at Southgate.

1996. The external form of domestic animals has been much studied, and the proportions are well ascertained. But the external form is an indication only of internal structure. The principles of improving it must, therefore, be founded on a knowledge of the structure and use of internal parts.

1997. The lungs are of the first importance. It is on their size and soundness that the strength and health of animals principally depends. The power of converting food into nourishment, is in proportion to their size. An animal with large lungs is capable of converting a given quantity of food into more nourishment than one with smaller lungs; and therefore has a greater aptitude to fatten.

1998. The chest, according to its external form and size, indicates the size of the lungs. The form of the chest should approach to the figure of a cone, having its apex situated between the shoulders, and its base towards the loins. Its capacity depends on its form more than on the extent of its circumference; for where the girth is equal in two animals, one may have much larger lungs than the other. A circle contains more than an ellipsis of equal circumference; and in proportion as the ellipsis deviates from the circle it contains less. A deep chest, therefore, is not capacious; unless it is proportionably broad.

1999. The pelvis is the cavity formed by the junction of the haunch bones with the bone of the rump. It is essential that this cavity should be large in the female, that she may be enabled to bring forth her young with less difficulty. When this cavity is small, the life of the mother and her offspring is endangered The size of the pelvis is chiefly indicated by the width of the hips, and the breadth of the waist, which is the space between the thighs. The breadth of the loins is always in proportion to that of the chest and pelvis.

2000. The head should be small, by which the birth is facilitated. Its smallness affords other advantages, and generally indicates that the animal is of a good breed. Horns are useless to domestic animals, and they are often a cause of accidents. It is not difficult to breed animals without them. The breeders of horned cattle and horned sheep, sustain a loss more extensive than they may conceive; for it is not the horns alone, but also much bone in the skulls of such animals to support their horns, for which the butcher pays nothing; and besides this there is an additional quantity of ligament and muscle in the neck, which is of small value. The skull of a ram with its horns, weighed five times more than a skull which was hornless. Both these skulls were taken from sheep of the same age, each being four years old. The great difference in weight depended chiefly on the horns, for the lower jaws were nearly equal; one weighing seven ounces, and the other six ounces and three quarters, which proves that the natural size of the head was the same in both, independent of the horns and the thickness of bone which supports them. In horned animals the skull is extremely thick. In a hornless animal it is much thinner, especially in that part where the horns usually grow. To those who have reflected on the subject, it may appear of little consequence whether sheep and cattle have horns; but on a moderate calculation it will be found, that the loss in farming stock, and also in the diminution of animal food, is very considerable, from the productions of horns and their appendages. A mode of breeding which would prevent the production of these, would afford a considerable profit in an increase of meat, wool, and other valuable parts.

2001. The length of the neck should be proportioned to the height of the animal, that it may collect its

food with ease.

2002. The muscles, and the tendons which are their appendages, should be large; by which an animal is enabled to travel with greater facility.

2003. The bones, when large, are commonly considered an indication of strength; but strength does not depend on the size of the bones, but on that of the muscles. Many animals with large bones are weak, their muscles being small. Animals that have been imperfectly nourished during growth, have their bones disproportionately large. If such deficiency of nourishment originated from a constitutional defect, which