30 



FIRST CLASS OF THE VERTEBRATED ANIMALS. 



tongue is originally small as we find in the Fishes. The nose and ear present no 

 external projection, in which respect they again resemble these organs in the Cetacea, 

 and in the great oviparous animals. Again, the eye appears at first without an eye- 

 lid, as it is always found in Insects, the Crustacea, the MoUusca, the Fishes, and 

 certain Reptiles. 



Finally, the general form of the human embryo does not exhibit a less degree of 

 analogy with the perfect states of other animals. The head is at first so slightly de- 

 veloped, as to give to the body of the embryo the appearance of an Invertebrated 

 Animal. It resembles a Fish or a Reptile by the absence of limbs ; and the caudal 

 or tail-like appendage, which we have already mentioned, gives it for a short time the 

 aspect of an ordmtu-y quadruped. 



From what has been said, it appears that the embryos of the higher animals exhibit 

 in the course of their growth the greater part of the characteristic peculiarities of 

 all classes of animals, and present the fleeting models of almost all the different kinds 

 of organization. The rudiments of Man thus form a reduced, yet striking, image of 

 the entire Animal Kingdom, 



We must admit, however, that these resemblances which have just been enume- 

 rated are far from establishing among all beings a perfect and absolute identity, 

 whether we consider different animals in their states of perfection, or upon comparing 

 one animal at the different ages of its progress, and with other animals of different yet 

 inferior species. Every animal preserves continually, and throughout every age, certain 

 well-marked characters peculiar to its species. These differences are so striking, 

 even in those which appear to resemble each other most nearly, that it becomes 

 impossible for us to conclude, that they may all be arranged in one graduated scale, 

 every where complete and continuous; or that they all possess one common frame- 

 work, one visible and identical basis, with the same number of essential organs, pos- 

 sessing the same natural characters. Still less can they be supposed to be derived 

 by gradual metamorphoses and complications from one common stock, from binary, or 

 even from ternary types. These analogies being always pai'tial, and frequently vague, 

 can by no means warrant the adoption either of the universal chain of existence pro- 

 posed by Bonnet, or the transmutation of species, and the successive filiation of 

 Demaillet and Lamarck. Still less will they admit the adoption of the organic 

 identity proposed by certain French and German writers. 



If animals resemble each other universally, it is only in the great phenomena of 

 existence, of which we have already treated. When, however, we descend to the 

 instruments producing these phenomena, we are surprised to find the most striking 

 difference, instead of resemblance, which can be considered as perfect. One animal 

 seemingly superior to another in some of its organs, is often evidently inferior to 

 the same animal in other details of its structure. We sometimes find that two animals 

 which resemble each other entirely in respect to one set of organs, are sometimes so 

 dissimilar in their conformation, that it is impossible to blend them together even in 

 imagination. Finally, there are some organs of which certain entire classes of ani- 

 mals are altogether deprived, and yet they may exhibit, in two other classes of animals 

 apparently allied to each other, the most discordant characters. Indeed, it is cer- 

 tain that there is not a single organ which does not vary from one genus or from 

 one family to another; but at the same time, there is not an organ, except perhaps 

 the stomach, which can be found in all families and in all genera. We shall see 

 numerous proofs of this in the details of the Animal Kingdom. 



The real cause of analogies among different ages and species must be found in this, — 

 that they are all constructed upon models evidently analogous. The same Divine 

 Artificer formed them all. We find the same style in every page of the great book 

 of Nature ; and we every where see the most evident affinities both in the essential 

 organs of animals, and in the phenomena which they exhibit. 



From what has already been said, we may easily perceive the cause of those wonder- 

 ful productions, those Lusus NaturcBy or monstrous births, which in all ages have 

 astonished and alarmed the ignorant. These evidently ai'ise from a retardation in the 



growth of some organs. An animal, though remaining incomplete In regard to one 

 organ, may yet continue to grow in all other respects, and the disproportion of the 

 organs may thus proceed to the most shocking disparity. Another consequence of 

 this law is, that the abortive and imperfect organs of an animal must resemble the 

 usual organs of the same animal in an earlier state of its existence, or those of a lower 

 animal in an adult form. Though all the organs may have been originally perfect, 

 yet if one ceases to develop itself, while all the others continue their progress, the 

 monstrosity of the final result is the necessary consequence. 



It follows also, that what is a deformity in one animal, may be a constant and per- 

 manent character of another. The monstrosity of a higher animal may bear a decided 

 analogy to the regular form of one of another grade. For example, it is evident that 

 one of the Mamm-alia, born without hair, is analogous to the lowest classes of ani- 

 mals having the skin naked. If the skin be scaly, it brings the Quadrupeds down to 

 the level of the Fishes and the Ophidian Reptiles. The Mammaha and Man often 

 have a divided palate, like the Birds, the Fishes, and many Reptiles. The occasional 

 absence of the teeth in Mammalia may be explained on the same principle. The mon- 

 strous development of the hver is found naturally in Birds, Fishes, and also in some 

 Cetacea and Reptiles. To want the tongue, or to have it forked — to have the hmbs 

 abortive, or altogether wanting, though monstrous developments, are natural and 

 constant aiTangements in other species. 



The following are the most remarkable of the laws of Monstrosity, or, as Lord Bacon 

 calls them, " the laws which govern the sports of Nature:" — - 



1. Monstrosities are always found more frequently in females than in males. The 

 cause of this is to be found in the fact, that the male sex is a more advanced state 

 of development than the female. All embryos, of whatever sex they may ulti- 

 mately be, arc at one time females. In infancy, too, the female character predomi- 

 nates. Young boys preserve for many years the smooth chin, the narrow larynx, the 

 silver voice, and the rounded hmbs of the young female. The young birds of both 

 sexes have at first the same plumage as their mothers, and moult at the same time 

 that they do. The same thing holds with all the other characteristics of the male 

 sex. The mane of the Lion, the crests, spurs, and other ornaments of the male 

 Birds, the antlers of Stags, the horns of Cattle, the vivid colours and powerful energy 

 which belong to the males of different species, are all characters slow in developing 

 themselves. 



2. Monstrosities never exceed certain limits, and deformities have their fixed laws. 

 Thus, when there ai-e supernumerary fingers, they are always similarly disposed. 



3. They always preserve a degree of symmetry, even among the most shocking 

 irregularities. A double monster seems to result from the same law, which occasions 

 both sides of the body to be symmetrical. 



4. The absence or excessive smallness of one organ is always followed by the ex- 

 treme development of another. 



5. Monstrosities are more frequently found in the left side than in the right, be- 

 cause the left side is always the more feeble and imperfect. 



6. Deformities generally go together in pairs. Thus, the presence of supernume- 

 rary fingers and the division of the palate ; the excessive smallness of the lungs, with 

 a great development of the liver ; and these dispositions, which usually co-exist in 

 monsters, are found naturally in many animals. 



7. The most diversified organs of the animal series are the most liable to monstro- 

 sity in the higher animals. 



8. Monsters always have some of their organs below their age, and consequently 

 below their class, but never above them. A monstrous Bird or Quadruped often has 

 its organs analogous to those of a Reptile or of a Fish ; but a Fish or Reptile never 

 has those of a Bird. This rule is general and constant. 



Several more laws might be mentioned, but these seem sufiicient for our present 

 purpose. We shall now proceed to consider the Animal Kingdom more in detail, and 

 accordingly commence with the Mammalia. 



THE FIRST CLASS OF THE VERTEBRATED ANIMALS. 



THE MAMMALIA— MAN AND BEASTS. 



V/ITH WARM ELOOD; HEAUT WITH TWO VENTRICLES; FEMALES SUCKLING THEIR YOUNG WITH MILK SECRETED IN BREASTS OR MAUMJE; VIVIPAROUS 

 EXCEPTING THE MONOTREMATA, WHICH ARE EITHER OVIPAROUS OR OVO-VIVIPAROUS. 



The Mammalia should be placed at the head of the Animal Kingdom, 

 not only because it is the class to which Man himself belongs, but be- 

 cause it surpasses all others in the enjoyment of more numerous facul- 

 ties, of more delicate sensations, of a greater variety of motions, and 

 where all these properties are combined so as to form beings of greater 

 intelligence, fruitful in resources, less the slaves of instinct, and more sus- 

 ceptible of improvement. 



This class possesses characteristics peculiar to itself, in its viviparous 

 generation [the young being born alive], in the manner by which the 

 foetus [or embryo] is nourished in the womb, by means of the placenta, 

 and in the mamm^, or breasts, by which the young are suckled. 



On the contrary, the other classes are oviparous [or produced from eggs 

 previously laid by the parent] ; and if we contrast them generally with 

 the Mammalia, we shall find that they possess numerous points of resem- 



blance among themselves, which clearly exhibit a special plan of organiza- 

 tion in the general system of the Vertebrated animals. 



As the degree of their respiration is moderate, the Mammalia are in 

 general adapted for walking upon the ground, but at the same time their 

 movements are performed with vigour, and in a continuous manner. 

 For this reason, the articulations of their skeletons have very precise 

 forms, which determine the direction and extent of their motions with 

 precision. 



Some of them can, however, raise themselves in the air by means of 

 elongated limbs, connected by extensible membranes; others have their 

 limbs so much shortened that they cannot move easily except in the 

 water. But this circumstance by no means deprives these last-men- 

 tioned animals of the general characters of the class. 



This variety in the character of their locomotion requires a corresponding differ- 



