618 
tUbteto. 
Quid sit pulchrum, quid turpe, qu ; d utile, quid non.—H or. 
Bridgewater Treatises , No. 5. Animal and Vegetable Phi/si - 
ology, considered with reference to Natural Theology. By 
Peter Marle Roget,M.D., Secretary to the Royal Society, 
6)C. 2 vols, 8vo.—London, 1834. Pickering. 
Dr. Roget has treated his subject in a masterly manner; and 
has supplied a desideratum that has been long called for, namely, a 
popular treatise on Comparative Anatomy in our language. He 
commences by discussing final causes and the functions of life 
in general; and then proceeds to divide his subject into the 
mechanical, vital, sensorial, and reproductive functions. Each 
of these he traces up from their earliest development in the 
lowest scale of existence to their highest state of perfection in 
the animal kingdom. It would be a pleasing task for us to fol¬ 
low him in this highly interesting subject; but in a publication 
like ours, we must be contented with a few of the interesting 
facts that most intimately concern us as veterinarians. 
The author has embellished his work with a multitude of well 
executed illustrative woodcuts, the existence of which consider¬ 
ably restricts us in our choice of extracts. He thus describes 
the mechanical functions of mammiferous quadrupeds in general. 
“ The office of the limbs, as far as they are concerned in pro¬ 
gressive motion, is twofold. They have to sustain the weight 
of the body, which they must do by acting in opposition to the 
force of gravity; and they must, secondly, give the body an im¬ 
pulse forwards. 
The limbs of quadrupeds constitute four columns of support 
to the trunk, which is placed horizontally above them ; but the 
whole weight of the body, together with that of the head and 
neck, does not bear equally upon them : the fore extremities 
almost always sustain the greater part of that weight, both be¬ 
cause the fore part of the trunk is itself heavier than the hind 
part, and because it is loaded with the additional weight of the 
head and neck. Hence, in the usual attitude of standing, the 
pieces of which the fore limbs are composed are required to be 
placed more in a straight line than those of the hinder limb; 
for the power of a column to support a weight is the greater in 
proportion as it approaches to the perpendicular position. The 
hind limbs are composed of exactly the same number of divi¬ 
sions; but the separate portions are usually longer than those of 
