1094 Growth, its Conditions and Variations, [November — 
With respect to active animals their food-taking powers depend | 
on one or more of three requisites, speed of motion, mental — 
quickness and power of weapons. The largest animals among | 
the Carnivora are those which have the highest development of | 
this third requisite, and thus can obtain equal quantities of food — 
with less organic exhaustion. It is not necessary to make a com 
parison of the weapons of various animals in this connection, a 
it is evident that there is a steady progression upwards as we 
` pons grow more powerful, from the Protozoan cilia to the Mam 
malian claws and teeth. 
But a highly important influence in this connection is that of 
special adaptation of animals to particular kinds of food, together 
with the comparative abundance of this food, and its comparative 
resistance to capture. The food of carnivorous animals does net 
tamely submit to destruction. It makes earnest efforts to escape 
or to defend itself. With animals that depend for safety on 
flight, and for food on pursuit, the great muscular exertion acs 
to check growth. Yet if these animals are capable of obtaining 
plentiful food they may become of considerable size. The wee 
sels and their congeners are adapted to a kind of food which ® | 
small in bulk and is only to be obtained by great agility or cu 
ning, often by pursuit through underground burrows. e” 
their size is necessarily restricted, since overgrowth w uld food ; 
them for their life habits, and thus still further reduce theit 10% 
supply. Their burrowing prey also are necessarily of gao 
from the exigencies of their life habits and the small q E 
of food which they are capable of obtaining. On the other 6 
the much chased deer are grass eaters, and are thus ie 
an abundant food which can be obtained without exertion ~ 5 
therefore attain a considerable size despite the great as 
exertion which they need for safety. At the same time the a 
Carnivora, which feed upon the timid Herbivora, pe grt 
large masses, and grow in bulk accordingly, despite. : 
activity. = close 
With the Herbivora the same rule holds. Their bulk is ie 
governed by the degree of agility necessary to olita mi 
resistance of this food to capture, its comparative abundanc® ie 
the exertion which they need to escape carnivorous wage 
nut-eating rodents, for instance, depend upon food ne a 
ine 
_ Capture, and which can only be obtained in small qué : 
