so 



FIRST CLASS OF THE VERTEBRATED ANIMALS. 



that daily sleep of BTan and the lower animals during the hottest parts of the day, and 

 called the siestc in Spain and Italy. 



Neither cold nor heat can thus be said to be the cause of hybernation and testi- 

 vation, although they arc auxiliaries to those states. In the same manner as it is 

 neither cold nor heat that compels us to sleep every night, but a constitutional fatigue, 

 and the necessity of repairing our forces ; so in these annual sleeps the absence and 

 presence of heat are merely proximate causes. Nature has wisely constituted 

 these animals thus ; for it is probable that their feeble constitutions would have 

 otherwise failed to resist the cold, or they would perhaps have been unable to procure 

 an adequate supply of food. When the period of torpidity is over, the rutting season 

 usually commences, and these animals then enter anew upon the functions of life with 

 renovated faculties. 



GENERAL REVIEW OF THE MAMMALIA CONTINUED. 



. Phenomena of Reproduction — Growth — Duration of Life. 



Scarcely have the Mammalia attained the full period of their growth, when another 

 order of functions make their appearance. Their animal forces then acquire a new 

 direction, and Life, which was formerly confined to the development of the individual, 

 now applies itself towards the conlinuation of the species. 



The time when the phenomena of reproduction first exhibit themselves- is termed 

 Puberty. Then the reproductive organs, which previously were but slightly apparent, 

 acquire a remarkable development, and in some species obtain certain external cha- 

 racters which remain during the whole course of their lives. Infancy is the period 

 comprised between birth and puberty. It is during the time preceding puberty that 

 the growth of the body chiefly takes place, although it may continue for some time 

 afterwards. The length of the period of infancy bears to that of life a certain relation, 

 ■which may be regarded as almost constant. Buffon remarks, that in our climates, 

 for the largest animals, it is about the one-seventh part of their entire life. 



At the age of puberty, the Mammalia assume the characters of maturity. Their 

 height attains its greatest limit, and the distinctive marks of each animal become 

 bold and well-defined. The physiognomy assumes a more animated expression ; their 

 voice becomes hoarser or stronger, and the fur handsomer ; while the vivacity of their 

 movements marks the impetuosity of those passions which animate them at this epoch. 

 The male becomes distinguished from the female by colours which are commonly 

 darker or browner, and in many species by certain definite external characters. 

 Thus, some male Apes acquire a beard and a coat of long hair ; the Lion obtains a 

 mane ; and the -Stags and Roebucks are armed with branching horns, of which the 

 females are nearly always deprived. The He-Goats and Rams are at once distin- 

 guished from the females by their horns, their masculine gait, and combative dispo- 

 sition. This superiority in the males is most marked among the Ruminantia, which 

 are commonly polygamous, and where each male having several of the other sex to 

 keep in subjection, it becomes necessary to assign him a piiysical superiority, 

 ■unnecessary in the monogamous species, where the sexes are always more equal in 

 strength. 



' Puberty constantly exhibits itself much sooner in females than in males, although 

 the reproductive power remains longer with the latter than with the former. In our 

 climates Blan attains this condition at the age of fifteen or sixteen, and Woman 

 at that of fourteen or fifteen; in warmer climates it exhibits itself at the age of 

 twelve to fourteen in the former, and at ten to twelve in the latter. With most of 

 the other Mammalia, excepting the domestic animals, we are still ignorant of the pre- 

 cise periods when puberty commences. Dogs are capable of reproducing at the age 

 of nine or ten months ; Cats from a year to eighteen months. A Lioness of the " Me- 

 nagerie" at Paris was six years old when she exhibited these phenomena for the 

 first time. Rabbits can procreate at the age of five or six months ; Hares a little 

 later; and Guinea- Pigs at five or six weeks. Sheep show signs of puberty when 

 one year old ; Rams, He- Goats, and Stags, at eighteen months. Horses produce 

 at two years and a half, and Marcs a little sooner. Camels, according to the ancients, 

 at three years ; Wolves at two years ; Cows at eighteen months ; Bulls six months 

 later ; the She- Ass from eighteen to twenty months ; and the Ass at two years. It 

 is, however, the interest of the Grazier to prevent the domestic animals from pro- 

 creating before they have attained their full growth, otherwise the deterioration of 

 the races is sure to follow. 



There are certain seasons of the year when most Blammaha become susceptible of 

 the instincts of reproduction. This is termed the rutting season, during \\hich the 

 usual character of the animals is totally changed, especially of the males. The most 

 timid animals, being excited by the abundance of food and the internal suggestions of 

 instinct, acquire a degree of courage and even fury, which urges them on in a career 

 of madness, which can be compared only to the habitual ferocity of the most formi- 

 dable species. The females also, at this period, lay aside their habitual reserve, and 

 are seen to provoke the males by biting, teasing, and following them everywhere. 



Some Mammalia in our countries, as well as in those of the south, whether males 

 or females, remain always in a state adapted for procreation, after having once 

 attained the age of Puberty. With the exception of the I^Ionkeys, this happens 

 only to those species, which either receive an abundant nourishment from Blan, 

 or else obtain a plentiful supply by plundering his stores. Of the first kind are 

 the Dog, Cat, Rabbit, Guinea-Pig, Hog, Bull, Buffalo, Horse, and Ass; in the 

 second division must be placed the common Rat, the common Mouse, the Wood 

 Mouse, the Economic Mouse, and the Hamster. With the animals of the IMe- 

 xiagerie, the change of climate which they experience, and the constraints of con- 

 finement, occasion them to imdergo certain deviations from their natural period of 

 Tutting. Among these may particularly be enumerated, the Lion and other Cats 

 from warm chmates, the Cape Ichneumon {Mangusta grisea), and the Cape Genet 

 {Paradoxtirus iypus), the Ichneumon of Egypt, the Gnu Antelope, and the Zebra; 

 also the Asia X)eec ii'oin the hanks of the Ganges, and the Kangaxoo of New 

 Holland 



It commonly happens, however, with the Mammalia, when they have not been 

 modified by domestication or confinement, that each has a peculiar season when the 

 phenomena of the rut more especially present them&elves. Thus, winter is the rut- 

 ting time of the Wild Cat and IMartens of Europe ; of the Wolf, from December to 

 February; of the Jackal and Corsac Fox (Canis Cornac)^ only in winter. The 

 Arctic Fox ( Cayiis lagnpiis) is in season at the end of February ; the Bear, in sum- 

 mer ; the Hedgehog, at the end of winter ; and the Hare in February or March. 

 The Beavers seek the females in the beginning of January ; the American Ondatra 

 and the Common Squirrel, in spring. The Dromedaries seem to be more in season 

 about the month of January than at any other time. Camels begin about the middle 

 of November, and end at the commencement of February. The month of Septem- 

 ber is the chief time for the Sheep and Goats, although the males of both species are 

 always fit for procreation. In the Stags of our coxmtries, the Roebuck, and other 

 Deer, the rutting season succeeds to the period when the horns are renewed, that is 

 in November, and after this time the horns fall. The Rein- Deer are in the same case. 



Thus the season of the rut varies with the species; but it is always so arranged 

 in reference to the term of gestation, that the young may make their appearance at 

 a favorable season of the year, when the heat of sumrocr will serve to aid their 

 growth, and assist in developing their forces. At this season, also, a luxurious 

 vegeta.tion supplies the herbivorous animals with abundance of food, which favors 

 the secretion of milk, and ensures its continued supply. 



The external signs of the rutting period vary greatly with the several species. In 

 those which are capable of procreating at all seasons, such as Man, the Monkeys, 

 Dogs, Cats, and Horses, no particular sign is observed. It is different with the- 

 Rodentia. " Dans la plupart des Rongeurs (Rodentia), les testicules, ordinaireraent 

 petits et comme caches dans I'abdomen, prennent un volume tres considerable et 

 deviennent fort apparens. C'est en particulier, ce qu'on remarque dans les Rats, 

 les Sxn-mulotsetc. ou ces parties font, k cette epoque, une saillie tres-remarquable a 

 la base de la queue, et donnentau corps une figurepointue vers cette extrernita." At 

 this period the Elephants secrete, on the side of the head behind the ears, a brownish 

 fluid, which proceeds from gland? situate under the skin. The Baetrian Camel diffuses 

 a most disagreeable odour at this season. At first he undergoes a violent perspiration, 

 which lasts for fifteen days ; then a blackish and viscous fluid exudes from the neck, 

 not through any particular opening, but merely from the pores of the skin, so that 

 the Persians are obliged to cut his hair very close. In the Dromedary, also, the 

 male presents at this particular season a similar phenomenon. We find, likewise, that 

 all. those odoriferous Mammalia, which are supplied with pouches from whence the 

 odours emanate, emit their perfum-'S at this time with unusual force. In the greater 

 number of animals belonging to the Deer Genus, and in several Antelopes, the 

 larynx or windpipe of the male projects considerably; and it cannot be doubted 

 that the change of tone which his voice undergoes is owing to this cause. 



It usually happens that the females exhibit the external signs of the rutting season 

 in a milder and more subdued form than the males. ** Alors sculemenl, observes 

 M. Desmarest, '*les organes externes de la generation se tumefient legei"ement, 

 s'entr'ouvrent, et sont continuellement humectes par un fluide plus ou moins vis- 

 quoux, qui, chez les jumens, ou il est particulierement abondant a recu le nom dliip- 

 pomanes. Neaumoins, la tumefaction et la rongeur excessive des fesses decertaines 

 femelles de singes doivent etre considerees comme un signe du rut, et sans nui doute 

 aussi, les ecoulemens sanguins qui ont heu a des epoques regulieres et plus ou moins 

 rapprochees, mais fixes chez celles de quelqa.es especes." These appearances may 

 present themselves in the females at intervals more or less considerable in the course 

 of the year. 



Among the Mammalia, and indeed in all living beings, the period of puberty and 

 reproduction is one of energy and strength ; all their affections become more ardent, 

 and their wants irresistible. The term ?'z/f, from ruere, to rush headlong, serves to- 

 express the fury which transports these lower animals. 



In furias ignesque ruunt, amor omnibus idem. 



Alike ferocious and untameable, they are susceptible at this period neither of fear 

 nor any other passion, and seem deaf even to the calls of hunger or sleep. The Bull 

 forsakes the meadows, and rambles everywhere in search of his mate. The forests 

 resound with the howling of contesting Wolves, and the Lion, with a deafening roar, 

 defies his rivals to the combat. We may easily perceive the final cause of these 

 contests among the lower animals during the rutting season. Nature ever sacrifices 

 the interests of individuals towards the perfection of species. The most vigor- 

 ous males always possess thj most formidable weapons of attack and defence, while 

 the more effeminate individuals exhibit their feebleness at once in their horns and their 

 want of courage. It is especially among the polygamous races where these combats 

 of the rutting season are more conspicuously observable, because each male fights for 

 several females. In the monogamous species, on the contrary, where the numbers 

 of the sexes are nearly equal, these battles seldom occur. Again, in the Carnivora, 

 when the number of the males surpasses that of the females, duels become both fre- 

 quent and sanguinary. The Seals (Fhoca) are perhaps more polygamous than any 

 other of the JSIammalia. Each maintains a kind of seragho or family, composed, 

 perhaps, of one hundred and twenty females, which he defends from the approach of 

 any other male, with the utmost jealousy and rage. Other species, less faithful or 

 more complaisant, pass from conquest tu conquest, and pay their court to all the 

 beauties of the neighbourhood. 



The duration of this season varies with different species ; but, in general, among 

 the wild animals it ceases as soon as the females have been fecundated. With 

 most of the latter, the external signs of the rut immediately disappear; the females 

 resume their usual reserve, and repel with ruc'eness the approaches of the male. 

 There are exceptions, in the Monkeyp, the Mare, and tn our own species. The female 

 Babbit is likewise an exception, though only an apparent one ; as from the peculiar 

 formation of the matrix, she is susceptible of a twofold impregnation, or superfe- 

 tation. 



" Le mode d'accouplcraent varie peu dans les Mammifcres ; en general cet acte a 

 lieu comme dans nos especes doraestiques d'Europe. On avait dit, que ceux de ce» 



