When Alexander conquered India, he took one of King Porus’s largest elephants, Ajax, and labeled it, “Alexander, the son of Jupiter, dedicates this to the sun.” This elephant is said to have been found 160 years later. This is the earliest record I find of animal longevity. We have many tables since Flourens attempted, with great pains, to construct one, and from the latest of these at hand I select the following of those animals popularly supposed to be able to attain one hundred years or more: carp, 100 to 150; crocodile, 100; crow, 100; eagle, 100; elephant, 150 to 200; parrot, 100; pike, 100; raven, 100; swan, 100; tortoise, over 100. In point of fact, as E. Ray Lankester[30] says, we know almost nothing definite of the length of life of larger animals. Flourens considered that in mammalia we could find a criterion of the end of the growth period in the union of the epiphyses of the bones throughout the skeleton, and laid down the law that for both mammals and man longevity is, on the average, about five times that of this period of growth. We know far more as to the span of the shorter- than of the longer-lived members of the brute creation. We also know far more of domestic animals than of their wild congeners. The former doubtless have lived longer because better protected. Darwin wrote that he had no information in regard to the longevity of the nearest wild representatives of our domestic animals or even of quadrupeds in general, and various experts whom Lankester addressed upon the subject informed him that almost nothing was known of reptiles or crustacea, while the ichthyologist, Gunther, said, “There is scarcely anything known about the age and causes of death of fishes,” and Jeffreys, a molluscan expert, says the same of them. Insects, on the other hand, are a remarkable exception. Their life is so short that it can sometimes be observed almost continuously from ovum to ovum. There is in general, however, Lankester believes, a much closer relation between the life span of individuals of the same than between those of different species, specific longevity meaning the average length of life of the individual of the species. Of all this we know far more of man than of any other creature.