46 
GEOLOGY OF THE FIRST DISTRICT. 
form of the bones composing it; and as the latter are articulated to the humerus, any alte¬ 
rations in them must alter its figure. Animals which employ their fore limbs in seizing, must 
have strong shoulders ; the scapula and clavicle will therefore exhibit certain modifications. 
The muscles must have forms, size and strength suitable to the actions of which the bones 
and joints just enumerated are capable, while their attachments and contractions impress 
particular figures on those solid organs.” 
“ Similar conclusions may be drawn respecting the posterior extremities, which contribute 
to the rapidity of the general motions ; respecting the composition of the trunk, and the'form 
of the vertebra, which influence the facility of these motions ; respecting the bones of the 
nose, of the orbit and the ear, which have obvious relations to the degree of perfection in the 
senses of smelling, seeing and hearing. In a word, the form of a tooth determines that of 
the condyle ; the form of the scapula, that of the nails ; just as the equation of a curve indi¬ 
cates all its properties. As in taking each property separately for the basis of a particular 
equation, we might arrive not only at the ordinary equation, but at all the other properties of 
the curve ; so the nail, the scapula, the maxillary condyle, the femur, and all the other bones 
taken separately, would each indicate the kind of teeth, or would indicate each other recipro¬ 
cally ; and beginning with either separately, we might, according to the rational laws of the 
organic economy, reconstruct the whole animal.”* 
If the geologist find the nearer head of the radius of some animal, and see in its extremity 
a smooth depression where it bears against the humerus, and observe the polished circle 
where it rotates on the cavity of the ulna, he would say, this animal had a paw; it had a mo¬ 
tion at the wrist, which implies claws. Claws may belong to two orders of animals, viz. 
feline, having carnivorous teeth ; or to animals without teeth. If he should find the lower 
extremity of the same bone, and observe on it spines and grooves for the distinct tendons 
which disperse to the phalanges, he would conclude that the animal must have had movable 
claws ; that it was carnivorous, and he would seek for the corresponding canine teeth.f 
Again, suppose the bone found be the humerus, and on examination it proves to have a 
round head, and the tubercles near this head are depressed so as not to interfere with the 
revolving motion; such a form betokens a latitude and extent of motion. But freedom of 
motion in the shoulders implies also freedom in the extremity or paw, and rotation of the bones 
of the wrist. We now examine that part of the humerus which gives rise to the muscles for 
turning the wrist (supinator), and in the prominence and length of the ridge which is on the 
lower and outer side of the bone, we have proof of the free motion of the paw. We conclude, 
from the bone thus characterized, that it belonged to an animal with sharp movable claws, and 
“ that in all probability it is the remains of a bear.” 
Suppose, again, that the head was not so round as in the last case, and that the tubercles 
project so as to limit the motion. On such a humerus we shall find on the lower end a hinge 
* Recherches sur les Ossemens fossiles, Prel. discours ; Cuvier, Anat. Comp. Vol. 1, p. 45; Bost. Journal Science, Vol. 1, p. 
261: Mitchill’s Am. Ed. of Cuvier, 
t Bell on the Hand. 
