82 
FIRST CLASS OF THE VERTEBRATED ANIMALS. 
Hares and Rabbits ; 31 days in tbc Dormice ; four weeks in the Squirrels and Hats ; 
ami three weeks in the Guinea Pig. Among the Pachydermata, gestation is of much 
longer duration ; it endures with the Elephant from 22 to 23 months ; it lasts from 
1 1 to 12 months in the Horse and Ass ; in the Zebra for a year and some days ; in 
the Tapir, from 10 to li 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 
fem.ile3 of the common Red Deer (^Ceruus ehphus^t the Fallow Deer (C. dama), 
and the Rein Deer fC. 7'arandii8) ; five months and a half for the Roebuck (C. 
caprtohat) ; five months for tlio Goat, tho Sheep, the IMouflon, 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, arc in general more con- 
siderable in proportion as the site of the animal is less. The Guiiica Pig can produce 
evei7 two months ; the Hamsters, the Rats, the Mice, the Ficld-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 
fem.ale of the Boar from three to eight. 
The number of young in each Utter 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 ISIole, from four to five ; and tho 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 tho brown Rat, or Surmulot, from eight to ten. The Agouti bears four, ac- 
cording to Laborde, or only two, according to Buffon 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 Marmot 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. With the exception of the Pig, the PachyderraaU 
produce but few young at a time; thus, the Elephants, Rhinoceroses, Hippopotamus, 
Tapir, and all the Horse genus, have only one; tho Peccari has two, while the female 
Pig will bear as many as twelve, and even twenty. All tho 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. It most commonly happens that tho 
first and last litter of each animal are deficient in number, and often also in strength. 
It thus appears, th.at the largest and most formidable species arc 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 tho 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. 'I’he' breed of Mice, for in- 
stance, would have long auico been blotted from the eartli, were the Mouse as slow 
in production as the Elepliant. But it has been widely provided, that such animals 
as can make but little resishmcc, should at least have a means of repairing tho de- 
struction, which they must often suffer, by their quick reproductiou ; that they should 
increase even among enemies, and multiply under tho hand of tho destroyer. On 
tho other hand, it has as wisely been ordered by Providence, that the larger kind 
should prodace but slowly ; otherwise, as they require proportional supplies from 
Nature, they would quickly consume their own store; and, of consequence, manv of 
them vrouhl soon perish through want, so that life would thus bo 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 assbted the weakness of one, by granting it fruitfulness ; and 
diminished tho number of the other by infecuiidity.” 
Thus in general, it would appear that the fecundity of animals is greater in proportion 
as they are more liable to perish from oxtornal c.iuses. Insects, plants, and the 
smaller species of IVIammalia, which cannot escape from danger, are exceedingly fer- 
tile, because Nature diminishes tho 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 monogamous 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 tho cares of their family between thorn, 
A mutual tenderness seems to prevail in these little societies, which are connected 
by affection alune. 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 iVlan, whose articulate language is here supplied by a natural system, 
where cries and gestures supply tho 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 ceaso to recognize 
each other after a certain time, and become wholly indifferent to the nearest 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, tho mother bears a much less number 
of young at a time than the monogamous kinds, and hence the female suffices to 
nourbh and protect them. The polygamous species being gencmlly also herbivor- 
ous, and tlie young being capable of walking from the moment of their birth, they 
are sooner able to subsist without tho aid of their parents than the Carnassiers. 
The latter, accordingly, are monogamous 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 limitwl 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 fiock of twenty Cows or Ewcj*. 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 different species arc 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 dillerent 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 tho Horse and Ass, the Buflalo and Cow, the Bison 
and Zebu, the Camel and Dromedary, all the corahinations in pairs among the 
Wolf, Fox, Jackal, and Dog; between tho Ram and Goat, the Haro 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 Mare, tho Ass with tho 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, arc 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 Mamra® to these viviparous quadrupeils. 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 specie*. 
This gemelliparous property is often peculiar to particular families. Twin brothers 
are often the fathers of twins at several successive births, ami 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 hnpperis 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 arc born with their eyes dosed, 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 others. 
As soon as the young arc born, their mother takes a peculiar care of them, until 
tlicy are sufficiently strong to find a maintenance without her aid. The female 
Rabbit prepares a bed of fur for her Utter, which she tears from the under part of 
her body a few days before producing. Tbc Shc-Boar collects hay and other soft 
substances in her retreat for a similar pui’pose. “ Whatever be the natural disposi- 
tion of animals at other times, they all acquire new courage, when they s 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,” continue* 
Goldsmith, “ of a She- Fox, which, when hunted, took her Cub in her mouth, and 
ran for several miles witliout quitting it, until at last she was forced to leave it be- 
hind, upon tho approach of a Mastiff, as she ran through a farmer’s yard. But if> 
this period, the mildest animals acquire new fierceness, bow formidable must those be 
that subsist by rapine! At such times, no obstacles can stop their ravage, and no 
threats can terrify ; tho Lioness then seems more hardy than even the Lion himselt- 
She attacks Men and Beasts indiscriminately, and carries all she can overcome reck- 
ing to her Cubs, which she thus early accustoms to slaughter. Milk, in tho Caf' 
nivorous animals, is much more sparing than in others; and it may bo for 
reason, that all such carry home their prey alive, that, in feeding their young» 
blood may supply the deficiencies of Nature, and serve instead of that milk, 
which they are so sparingly supplied. The choice of situation in bringing forth ** 
also very remarkable. In most of the rapacious kinds, the female takes the utmost 
precautions to hide the place of her retreat from tho male, who, otherwise, 
pressed by hunger, would be apt to devour her Cubs. She seldom, therefore, straj 
far from the den, and never approaches it while ho is in view, nor visits him 
till her young are capable of providing for themselves. Such animals as are 
tender constitutions, take the utmost care to provide a place of warmth, as well 
safety, for their young. Some dig holes in the ground ; some choose the hoUo'^ 
a tree ; and all the amphibious kinds bring up their young near the water, and 
custom them betimes to their proper element. The rapacious kinds bring forth 
the thickest woods.” 
