82 



FIRST CLASS OF THE VERTEBRATED ANIMALS. 



Hares and Rabbits ; 31 days in the Dormice ; four weeks in the Squirrels and Rats ; 

 and three weeks in the Guinea Pifr. Among the Pachydermata, gestation is of much 

 longer duration ; it endures with the Elephant from 22 to 23 months ; it lasts from 

 11 to 12 months in the Horse and Ass ; in the Zebra for a year and some days ; in 

 the Tapir, from 10 to 1 1 months ; in the Hog and Boar for four months. Further, 

 it endures among the Ruminantia, for twelve months in the Dromedary ; for nine 

 months in the female Buffalo and Cow ; for eight months and some days in the 

 females of the common Red Deer (Cervus elaphus), the Fallow Deer (C. da?na), 

 and the Rein Deer (C. Tarandus) ; five months and a half for the Roebuck (C 

 capreolus) ; five months for the Goat, the Sheep, the Mouflon, and several Ante- 

 lopes. We are hitherto without any positive information regarding the period of 

 gestation among the Cetacea. 



It is evident that the number of births appropriate to each species will mainly 

 depend upon the average length of each period of gestation. On this account, the 

 larger species do not produce every year, especially when a long term of lactation 

 also intervenes. The smallest species, on the contrary, multiply most prodigiously, 

 and it may be generally stated that, if we except the Rabbit and Hog, both the num- 

 ber of births, and the number of young ones at each birth, are in general more con- 

 siderable in proportion as the size of the animal is less. The Guinea Pig can produce 

 every two months ; the Hamsters, the Rats, the Mice, the Field-mice (^Arvicola)^ and 

 the Shrews, do not produce less than three or four litters in the course of the spring, 

 summer, and autumn. With respect to the exceptions above stated, it may be inferred 

 that the abundance of food which those animals obtain from Man has modified their 

 nature ; for we find that in all the wild species which approach nearest to these do- 

 mestic races, the number of young produced at each birth is always less, as may be 

 remarked in the Hare, producing only from three to four young at a birth, and the 

 female of the Boar from three to eight. 



The number of young in each litter also bears an immediate reference to the length 

 of gestation. At each birth, Man and the Quadrumana commonly produce only one, 

 very rarely two or more, and the Cheiroptera bear two. Among the Carnassiers, 

 the Tiger produces one; the Lion, three or four; the Cat, four or five ; the White 

 Bear, two ; the Brown Bear, from one to three ; the Wolf, the Fox, and the Adive, 

 from four to five; the Arctic Fox, from five to seven; the Badger, from three to 

 four ; the Mole, from four to five ; and the Seals, one or two. Among the Mar- 

 supialia, the Opossums produce from eight to ten, but the Kangaroos only one or 

 two. Of the Rodentia, the Beaver bears two or three at a birth ; the Rabbit 

 from four to eight ; the Hamster from five to six ; the common Rat, the Mouse, 

 and the brown Rat, or Surmulot, from eight to ten. The Agouti bears four, ac- 

 cording to Laborde, or only two, according to BufPon and d'Azara. The garden Dor- 

 mouse produces five or six young ones at a birth ; the common Dormouse three or 

 four; the Guinea-pig from seven to ten ; the common Squirrel from three to five ; 

 and the jMarmot three or four. Among the Edentata, the Sloths produce only one, 

 as also the Ant-eaters, while the Armadilloes bear four at each of their births, 

 which occur pretty frequently. AVith the exception of the Pig, the Pachyderraata 

 produce but few young at a time ; thus, the Elephants, Rhinoceroses, Hippopotamus, 

 Tapir, and all the Horse genus, have only one; the Peceari has two, while the female 

 Pig will bear as many as twelve, and even twenty. All the Ruminantia produce two 

 or more, excepting the largest species, which have only one. The Cetacea produce, 

 in general, but one young one at each birth. U most commonly happens that the 

 first and last litter of each animal are deficient in number, and often also in strength. 



It thus appears, that the largest and most formidable species are far less fruitful 

 than the smallest and weakest. Not only are the former longer in arriving at their 

 age of puberty, but their periods of gestation and lactation are prolonged, and the 

 number of young at each birth is, in general, less. Thus, while the Tiger produces only 

 one Cub at a time, the Wild Cat will bear four or five. " In this manner, the lower 

 tribes become extremely numerous ; and, but for this surprising fecundity, from their 

 natural weakness, they would quickly be extirpated. The breed of Mice, for in- 

 stance, would have long since been blotted from the earth, were the Mouse as slow 

 in production as the Elephant. But it has been wisely provided, that such animals 

 as can make but little resistance, should at least have a means of repairing the de- 

 struction, which they must often suffer, by their quick reproductiou ; that they should 

 increase even among enemies, and 'multiply under the hand of the destroyer. On 

 the other hand, it has as wisely been ordered by Providence, that the lar^-er kind 

 should produce but slowly ; otherwise, as they require proportional supplies from 

 Nature, they would quickly consume their own store ; and, of consequence, manv of 

 them would soon perish through want, so that life would thus be given without the 

 necessary means of subsistence. In a word, Providence has most wisely balanced 

 the strength of the great against the weakness of the little. Since it was necessary 

 that some should be great and others mean, since it was expedient that some should 

 live upon others, it has assisted the weakness of one, by granting it fruitfulness ; and 

 diminished the number of the other by infecundity." 



Thus in general, it would appear that the fecundity of animals is greater in proportion 

 as they are more liable to perish from external causes. Insects, plants, and the 

 smaller species of Mammalia, which cannot escape from danger, are exceedingly fer- 

 tile, because Nature diminishes the chances of death by those of life, so that the 

 species may exist continuously. The number of young at a birth thus serves as an index 

 to the probable perils of each species, as well as the voracity of its enemies. 



Among all the monogacnous species, such as several Rodentia, Bats, and Moles, a 

 kind of family is established during the interval, necessary for the support of the 

 young, when the father and mother divide the earej of their family between them. 

 A mutual tenderness seems to prevail in these little societies, which are connected 

 by affection alone. Each animal shares in the common labour, and each partakes in 

 its share of the produce. These societies, among many Rodentia, are almost as inti- 

 mate as those of Man, whose articulate language is here supplied by a natural system, 

 where eries and gestures supply the place of words. But when once the young 

 have become strong enough to maintain themselves without the aid of their parents, 

 they become estranged, and form other family connexions. They cease to recognize 

 each other after a certain time, and become wholly indifferent to the neai-est ties of 



blood. They even do not scruple to contract alliances with their nearest relations 

 of the other sex. It is seldom, however, that the young show any partiality of this 

 kind towards their older relations. On the contrary, this anomalous feeling nearly 

 always exhibits itself in the attachment of the older for the younger animals. 



With polygamous species, such as the Ram, Goat, and Bull, there exists no at- 

 tachment of relationship on the part of the male. Possessing several females, he has 

 no affection for his young, and the mother alone takes charge of them, during their 

 unprotected state of infancy. In these species, the mother bears a much leas number 

 of young at a time than the monogamous kinds, and hence the female suffices to 

 nourish and protect them. The polygamous species being generally also herbivor- 

 ous, and the young being capable of walking from the moment of their birth, they 

 are sooner able to subsist without the aid of their parents than the Carnassiers. 

 The latter, accordingly, are monoganaous in general. Their young are often born 

 with their eyes closed, and with imperfect senses. 



It may be remarked, that although the Herbivorous animals produce, in general, 

 only one or two young ones at a birth, this limited power of production is compensated 

 by the greater number of females which the males are capable of fecundating ; thus, a 

 single Bull or Ram is sufficient for a flock of twenty Cows or Ewes. But the Car- 

 nivorous animals, being chiefly confined to one female, produce a more numerous 

 race. It thus results in animals, as well as in man, that fruitfulness is the common 

 attendant of monogamy and chastity. 



Animals of difPerent species are destitute of the power of producing fertile races. 

 Not only are the individuals themselves naturally averse to unite, but there is found 

 a great variety in the forms of their organs of generation, and in their different pe- 

 riods of gestation, while the Hybrid produce, or Mule, is, in general, unfruitful. These 

 adulterous unions can hence only take place between animals which are very nearly 

 allied to each other, as between the Horse and Ass, the Buffalo and Cow, the Bison 

 and Zebu, the Camel and Dromedary, all the combinations in pairs among the 

 Wolf, Fox, Jackal, and Dog ; between the Ram and Goat, the Hare and the Rab- 

 bit. These animals are capable of mutually fecundating each other, whenever man 

 can succeed in overcoming their natural antipathy. But there are certain disparities 

 of organization, which wholly prevent the Dog from uniting with the Cat, the Bull 

 with the l\Iare, the Ass with the Cow, although some examples of the last kind of 

 union have been imagined. The unions between the larger species of Apes and 

 the human species, as well as their fabulous product, are not authentic, as some have 

 credulously supposed. 



Animals which produce more than one young one at a birth usually bear an even 

 number. This proceeds from the circumstance that each ovary supplies its contin- 

 gent of ovaria to be fecundated. In the same manner, Nature assigns an even 

 number of SlammEe to these viviparous quadrupeds. Human twins are most commonly 

 both males or both females, although sometimes they are male and female, but 

 these last happen more rarely. Four at a birth is very uncommon in the human species. 



This gemelliparous property is often peculiar to particular families. Twin brothers 

 are often the fathers of twins at several successive births, and in one case, a second 

 marriage having taken place, the latter wife produced twins likewise. In this kind 

 of generation, it is probable that the impregnation of the two ovaries happens at the 

 same moment, especially as we know that animals, habitually multiparous, only re- 

 quire a single union, although doubtless superfetation may also be induced by subse- 

 quent unions. 



The young of nearly all Mammalia are born with their eyes closed, and do not 

 open them for several days. The mother cuts the umbilical cord with her teeth, 

 and, even without being carnivorous, devours the membranes or after-birth, as in 

 the Cow, the Sheep, and many uthers. 



As soon as the young are born, their mother takes a peculiar care of them, until 

 they are sufficiently strong to find a maintenance without her aid. The female 

 Rabbit prepares a bed of fur for her litter, which she tears from the under part of 

 her body a few days before producing. The She-Bear collects hay and other soft 

 substances in her retreat for a similar purpose. " Whatever be the natural disposi- 

 tion of animals at other times, they all acquire new courage, when they-, consider 

 themselves as defending their young. No terrors can then drive them from the post 

 of duty ; the mildest begin to exert their little force, and resist the most formidable 

 enemy. Where resistance is hopeless, they then incur every danger, in order to res- 

 cue their young by flight, and retard their own expedition, by providing for their 

 little ones. When the female Opossum, an animal of America, is pursued, she in- 

 stantly takes her young into a false belly, with which Nature has supplied her, and 

 carries them off, or dies in the endeavour. 1 have been lately assured," continues 

 Goldsmith, " of a She-Fox, which, when hunted, took her Cub in her mouth, and 

 ran for several miles without quitting it, until at last she was forced to leave it be- 

 hind, upon the approach of a Mastiff, as she ran through a farmer's yard. But if, at 

 this period, the mildest animals acquire new fierceness, how formidable must those be 

 that subsist by rapine ! At such times, no obstacles can stop their ravage, and no 

 threats can terrify ; the Lioness then seems more hardy than even the Lion himself. 

 She attacks Men and Beasts indiscriminately, and carries all she can overcome reek- 

 inff to her Cubs, which she thus early accustoms to slaughter. Milk, in the Car- 

 nivorous animals, is much more sparing than in others ; and it may be for this 

 reason, that all such carry home their prey alive, that, in feeding their young, its 

 blood may supply the deficiencies of Nature, and serve instead of that milk, with 

 which they are so sparingly supplied. The choice of situation in bringing forth is 

 also very remarkable. In most of the rapacious kinds, the female takes the utmost 

 precautions to hide the place of her retreat from the male, who, otherwise, when 

 pressed by hunger, would be apt to devour her Cubs. She seldom, therefore, strays 

 far from the den, and never approaches it while he is in view, nor visits him again, 

 till her young are capable of providing for themselves. Such animals as are of 

 tender constitutions, take the utmost care to provide a place of warmth, as well as 

 safety, for their young. Some dig holes in the ground ; some choose the holl6w of 

 a tree; and all the amphibious kinds bring up their young near the water, and ac- 

 custom them betimes to their proper element. The rapacious kinds bring forth in 

 the thickest woods." 



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