190 NATURAL HISTORY. 
308. You see, then, that the brain, muscles, and other 
organs in the Reptile are stimulated with the mixture, 
which is not so stimulating or life-giving as pure arterial 
blood. It is therefore a less lively animal than those 
whose organs have arterial blood continually pumped 
into them by the heart. It therefore moves but little and 
slowly. Its circulation is slow, and so also is its breath- 
ing. 
309. But, while life is dull in reptiles, it is not easily de- 
stroyed. They will bear being maimed to a great ex- 
tent. If you destroy the brain or spinal cord of a warm- 
blooded animal, all signs of life soon cease ; but if this be 
done to a reptile, motions can be excited for a long time 
by pricking, or other modes of stimulation. The limbs 
of a turtle which has been dead for several days may be 
made to move by pricking them, showing that there is 
some life in their muscles still. So, also, the two parts 
of a snake cut in two will move independently for some 
time, and the tail of a lizard will move for some hours 
after it is cut off. The reptiles of temperate climates 
crawl into some secret place as winter comes on, and go 
into a state of perfect torpor which lasts tillspring. They 
are therefore called hibernating animals. 
310. The brain of reptiles is very small, for they have 
but little thinking to do. They have no special organ of 
touch, and their covering is such that they can have but 
little sensibility in it. The sense of taste and that of 
smell are dull. Vision is not very acute, and the appa- 
ratus of hearing is much less complete than in the warm- 
blooded animals. 
311. Almost all reptiles are carnivorous. The turtles 
and crocodiles divide their food more or less with their 
jaws; but the snakes or serpents swallow their food 
whole. In their case the throat can be so much dilated 
that they can swallow an animal larger than themselves. 
312. Reptiles are like birds in two things: they do not 
suckle their young, and they produce them from eggs. 
