34 
FIRST CLASS OF THE VERTEBRATED ANIMALS. 
In general, the HaAius forms the principal bone in the foro-arra of the Mammalia, 
while the Ulna is a slender and small bone, which is frequently consolidated with the 
radius, and terminates in a point before reaching the wrist. There are only a few 
genera which possess the power of rotating the wrist freely, so as at one time to pre- 
sent the palm of the hand downwards fpronationj^ and at another time tho palm of 
the hand upwards (st/pination^. This power diminishes in proportion as the fore 
extremities arc used for progression, and for supporting the body in standing. While 
in these positions, the fore extremity is always in a state of pronation. The radius and 
ulna are flattened in the Cetacea and Seal; and in the Elephant the lower extremity 
of the ulna is larger than that of the radius, a conformation which is peculiar to that 
animal. 
The Hand is formed of two rows of bones called the Carpus or Wrist; 
of one row called Metacarpus; and of Fingers, each composed of two or 
three bones, called Phalanges. 
The forms of the wrist and remote extremities vary with the delicacy of the organs 
of touch. It is only in few genera that a Hand, properly so called, is found ; but 
when it exists it is always much less complete, and therefore less useful than that of 
Man. The mechanism of the human hand is exceedingly curious, and admirably 
adapted for the various purposes of life. Anaxagoras is said to have maintained that 
Man owes all his wisdom and supcrt-lority over the other animals to the use of the 
hand ; but Galen’s view of the matter was rather more philosophical. According to 
him, Man is not the wisest creature because he has hands; hut he had hands given 
him because he was the wisest creature, for it was not hands that taught him tho 
arts, but Reason. The great superiority of tho human hand ovor that of any other 
animal, arises from the circumstance that his thumb is of a great size and strength, 
and can he brought in opposition to the fingers. It thu.s gives him the power of 
holding whatever he seizes; and wore it not for the thumb, various arts and manu- 
factures of civilized life would either remain unexecuted, or would require the awk- 
ward concurrence of both hands. Albinos calls the thumb a second hand. ** Manus 
parva majori adjutrixJ* The want of the thumb, and the absence of fingers of any 
great length, compel the Squirrel, Rat, and Opossum, to hold objects in both paws. 
The Cat and Dog, which are obliged to use their fore-paws for progression, only hold 
objects by fixing them on tho ground. Tho Solipeda and Ruminantia cannot hold 
objects at all. On comparing the hand of the Apes with that of Man, which it most 
resembles, we cannot fail to remark tho smallness of their thumbs in proportion to 
the length of the fingers. These are slender and very long, while the thumb is 
weak, small, and short. In the Corcopitheci, the thumb is concealed under the 
integuments, and their mode of seizing food and bringing it to the mouth differs but 
slightly from that employed by the Squirrel. The fore-foot of the Horse is termu 
nated by a single bone, called the coffin bone, corresponding in some degree to tho 
third phalanx of the human finger, as the pastern, to which it is united, is analogous to 
the first phalanx. There ai*e also two short and immoveable hones placed behind and 
on each side of the coffin bone, called splint bones. 
If we except the Cetacea, all the Mammalia have the first part of their 
hinder extremity attached to the spine, and formed into a Pelvis or Basin, 
which, during youth, is formed of three pairs of Bones, the Ileum, attached 
to the Spine; the Pubis, which forms the anterior; and the Ischium, 
forming the hinder part of the Pelvis. 
All these bones arc generally more narrow and elongated in the quadrupeds than in 
Man. In no instance do they form a basin like the human Pelvis ; while frequently 
the distinction between the large and small Pelvis does not exist, and the cavity often 
looks obliquely upwards, towards the Spine. One class of Mammalia, possessing 
abdominal pouches, have two small IMarsupid hones placed on the anterior part of the 
Pubis. These are of a flat and elongated form, and serve to support the abdominal 
pouch of the female; yet in some species they are also found in the male. 
At the point of union among the three bones of the Pelvis, is placed 
the cavity, to which the Thigh-bone or Femur is articulated. To this 
last bone is attached the Leg, composed of two bones, the Tibia or Shin- 
bone, and the Fibula. 
The Femur is remarkably short in quadrupeds having a long Metatarsus, as in tho 
Horse, and in common cattle ; and the bone is so enveloped with muscle, that the part 
usually called the thigh is really the leg. The Fibula, in many quadrupeds, bears a 
striking analogy to the Ulna of the fore-arm, from its decl'ning in size, and becoming 
united, by anchylosist with the Tibia, or else appearing merely in a rudimental form. 
This extremity of the Mammalia terminates in a Foot composed of 
parts analogous to those of the hand, namely, a Tarsus, Metatarsus, and 
Toes. 
These bones are altogether wanting in the Whale, Dolphin, ana other Sea Beasts. 
They have no pelvis, properly so called, as the Ischia are absent; yet we find two 
small isolated bones which may be compared to the ordinary Pubis. 
The head of the Mammalia is always articulated by two condyles upon 
their atlas or first vertebra. 
This name of Atlas is assigned to the first vertebra, because it sustains the globe of 
the head. Tlie second vertebra is called the DentaUiy or Axisy because it has a 
tooth-like process, or axis upon which the first turns. “ 1 challenge any man,” says Dr 
Paley, <‘to produce in the joints and pivots of the most complicated or the most 
flexible machine that was ever contrived, a construction more artificial, or more evi- 
dently artificial, than that which is seen in the vertebrae of the Human neck. Two 
things were to be done. The head was to have the power of bending forward and 
backward, as in the act of nodding, stooping, looking upwanb or downwards, and at 
the same time, of turning itself round upon the body to a certain extent, the quadrant, 
we will say, or rather perhaps a hundred and twenty degrees of a circle. For these 
two purposes, two tUstinct contrivances arc employed : First, the head rests immedi- 
ately upon the uppermost of the vertebra?, and is united to it by a Aiw^e-joint, upon 
which joint the head plays freely forward and backward, as far either way as is neces- 
sary, or as the ligaments allow, which was the first thing required. But then the 
rotatory motion is unprovided for. Therefore, secondly, to make tho head capable of 
this, a further mechanism is introduced — not between the head and tho uppermost 
bone of the neck, where the hinge is, but between that bone and the bone next 
underneath it. It is a mechanism resembling a ienor and mortice. The second, or 
uppermost bone but one, lias what anatomists call a process, viz. a projection some- 
what similar, in size and shape, fo a tooth; which tooth, entering a corresponding 
hole or socket in the bone above it, forms a pivot, or axle, upon which that upper 
hone, together with tho head which it supports, turns freely in a circle, and as far in 
the circle as tho attached m^cles permit tho head to turn. Thus are both motions 
perfect without interfering with each other. When we nod the head, we use the 
hinge-joint, which lies between the head and the first bone of the nock. When wc 
turn the head round, wc use the tenor and mortice, which runs between the first 
bone of the neck and the second. We may add, that it was on another account also 
expedient that the motion of the head, backward and forward, should be performed 
upon the upper surface of the first vertebra; for, if the first vertebra itself had bent 
forward, it would have brought the spinal marrow, at the very beginning of its course, 
upon the point of the tooth.” 
The Brain of the Mammalia is always composed of two hemispheres, 
united by a medullary layer called the Callous body {Corpus Callosum), 
inclosing two ventricles, and enveloping the four pairs of Tubercles, or 
eminences called the Striated Bodies {Corpiyra Slrhta)y the Beds of the 
Optic Nerves ( Thalami Nenjortm Opiicorum), the Kaiesy and the Testes. 
Between the Beds of the Optic Nerve is placed the third ventricle, 
which communicates wdth the fourth, situate under the Cerebellum. 
Tlie crura of the Cerebellum always form, under the Medulla Ohlongaia, 
a transverse eminence called the Bridge of Varolius {Tons Varolii). 
Tho Brain in the Monkey tribe is rather flatter in the superior surface of its he- 
mispheres than in Man; but in Quadrupeds it is very considerably flatter. In the 
Dolphin, and other Sca-Beaets, the Brain has a difTercnt shape from that of tho other 
Mammalia, being rounded in every part, wliilo its greatest diamoter is across. There 
are no olfactory nerves in the cetaceous animals, while those of quadrupeds are of an 
enormous size, especially in the larger herbivorous tribes. 
The proportion which the size of tho Brain bears to that of the entire Body, varies 
greatly for different Mammalia. Even in the sai;;o ii.dividual it will change with the 
degree of fatness, or with the age of the animal. As these circumstances cannot bo 
supposed to affect tho powers of the mind very materially, we may naturally inquire 
how the relative size of the brain, and of the entire body, can be assumed as the 
measure of intcUigonco in an animal. To enable the stedent to form his own con- 
clusions on this subject, we annex the following Table, showing the proportion that 
the size of the whole body bears to that of the Bral 
1 in several animals : — 
The Squirrel Monkey ( CallUhrix sewreus). 
as 22 
to 1 
Capuchin Monkey (Cebus capucbt7i$)y 
25 
... 1 
Striated Monkey (Jacckus vulgaris)y 
28 
... 1 
Field Mouse {Arricola vulguris)y 
81 
... 1 
Man, according as he Is young or old. 
as 22, 25, 30, and 36 
... 1 
The Mole (.Talpa Europtca)y 
- ■ . as 35 
... 1 
Coaita Monkey {Ateles paniscus)y 
41 
... 1 
Mouse {Mus musetdus). 
43 
... 1 
Varied Monkey {Ctrcopitliec7is mona)y 
44 
... 1 
Gibbon {Ililphates far). 
48 
... 1 
Collared Mangabey Monkey (Cercopxthecus JEthiops)y ... 48 
... 1 
Rat {Mus decumamts). 
76 
... 1 
Ruffed Lemur ( Lemur Macaco)y 
84 
... 1 
Porpoise {Deiphinus pkocama)y 
93 
... 1 
Great Bat ( Vesperlilio Noctula), 
96 
... 1 
Dolphin (Delphinn* dclphh). 
as 25, 36, 66, and 102 
... 1 
Great Baboon {Vapio Maivion), 
. . as 104 
... 1 
Barbary .\pc (Inuus magoUis)y 
105 
... 1 
Ferret (A/?#.v/6'/n yaro), 
138 
... 1 
Rabbit {Lepus cunicuhis). 
. as 140, and 152 
... 1 
Cat {Felia cnlus)t , , . 
as 82,94, and 156 
... 1 
Hedgehog {Erinaceus EuropcRvs)y . 
. as 168 
... 1 
Fox {Canis .... 
205 
... 1 
Calf {Bos tanrus ju.iiQr)y 
219 
... 1 
Hare {Lepus ivnidus). 
228 
... 1 
Wo\i {Cams lupHs)y 
230 
... 1 
Panther {Felis paj lus), 
247 
... J 
Ass {Equua asinus)y 
254 
... 1 
Bear {UrAUS arctoa)y 
265 
... I 
Beaver {Castor jiher), 
290 
... 1 
Sheep (Oyw , 
. as 192, and 351 
... 1 
Marten (f VrtTra marie/f), 
■ • . as 365 
... 1 
Dog {Canis familiaris), as 47, 50, 
57, 154, 161, and 366 
... 1 
Horse (Eguus caballus), 
• • . as 400 
... I 
Doraesiic Hog {Sua 8cropha)y . « 
412 
... 1 
Elephant {Ehphaa Indicus), . 
600 
... 1 
Wild Boar {Svs scropha), « 
672 
... 1 
Ox {Bos tanrus)y 
860 
... I 
From the above Tablo it would appear that the Brain is proportionably 
largest to 
^ , — o . 
the smaller animals. Man is surpassed in this respect only by a small number O' 
