In all ages the necessity has been recognized of operating upon animals that are nearest allied to man, such as the monkey, the hog, and the dog, and who share with the king of creation the privilege of eating a little of everything. Claude Bernard, however, had another way of looking at things. It is true that he especially made researches into the general laws of physiology, the secret of the vital functions, and the operation of the various organic systems that constitute living matter, but his immediate object was not to furnish weapons for the art of curing. He left to physicians and surgeons the care of drawing conclusions from his great work in biology, and of acting experimentally upon animals allied to man in order to found a rational system of therapeutics. So he preferred to operate upon beings placed low in the animal scale--the frog especially, an animal that has rendered him greater service than even man himself could have done. Cold-blooded animals offer, moreover, the advantage of being less impressionable than others, and the experiments to which they are submitted present more accurate conclusions, since it is not necessary to take so much account of the victim's restlessness. And then it is necessary in many cases to choose subjects that possess endurance. The unfortunate frog, so aptly named "the Job of physiology," becomes resigned to living under most dreadful conditions, and when, through sheer exhaustion, he has succumbed, his twitching limbs may still he used as an object of experimentation for twenty-four hours. Thanks are due to nature for giving so extraordinary a vitality to the tissues of a modest batrachian! We owe to it the famous experiment of Galvani that led Volta to the discovery of the pile and what followed it, the astonishing conquests of electricity and those more marvelous ones still that are now in their dawn. Science is much indebted to the frog, and may the homage that we pay him help to alleviate the sufferings that have been imposed upon this brave animal! [Illustration: Fig. 6-8 APPARATUS USED IN VIVISECTION.]