4 CHILDHOOD OF ANIMALS 



their character. The first group has little claim to existence ; it 

 contains a few animals that have no period of youth. The second 

 group contains very many of the animals with which we are most 

 familiar. The young are sufficiently like their parents to enable us 

 to make a close guess as to what they are going to become. We 

 have no doubt that a human baby is a young human being, that a 

 baby monkey belongs to the group of monkeys, although we may 

 not be quite certain as to the particular species of which it is a 

 member. It is the same with kittens, puppies, calves and lambs ; 

 we place them at once among the mammals, with complete certainty 

 in their own order, and with a probability that depends on our 

 powers of observation and knowledge in their proper family, genus, 

 or species. Young birds may puzzle us a little more, but at the 

 least we are never in doubt that the naked or fluffy creatures are 

 going to be birds. Crocodiles and lizards, snakes and turtles 

 similarly come into the world with their relationships plainly stamped 

 upon them. 



In the third group we must place those young animals, of which 

 many insects and marine creatures are familiar types, that are 

 so unlike their parents that their destiny cannot be guessed from 

 inspection. The changes through which many of these creatures 

 pass on their way to adult life are as strange as if a new-born 

 human baby were to have the form of a fish, swimming in a tank, 

 feeding greedily on worms and water-fleas, and then after a few 

 weeks or months were to grow very fat and sleepy, to split along 

 the back, and, discarding its fish-skin, to creep out on land in the form 

 of a hedgehog ; and if the hedgehog were to live for months or years 

 the life of a humble quadruped, growing bigger and fatter until it 

 too reached a limit of growth, broke out of its hedgehog skin and 

 appeared as an adult human being fitted in body and mind to be a 

 bishop or a burglar. 



It is not to be supposed that these three different kinds or aspects 

 of youth agree with the divisions in which the animal kingdom is 

 arranged by zoologists. It happens that the creatures without 

 a true period of youth belong to the lowest division of animals, and 

 that the highest animals fall naturally into the second group, but 

 the vast range of living beings between the lowest and the highest 

 divisions show all degrees of close likeness and complete unlikeness 

 to their parents. Nor must it be supposed that the three groups are 

 sharply marked off. The arrangement of facts in groups is more 

 convenient than natural, and we must not forget that many of the 



