ii8 CHILDHOOD OF ANIMALS 



large tracts of water become changed in colour because they swarm 

 with innumerable multitudes of tiny embryos. Sea-anemones 

 and jelly-fish, starfish and sea-urchins, the various tribes of worms, 

 crustaceans and molluscs, sea-squirts and fishes turn adrift a huge 

 and uncared-for progeny out of which a few lucky individuals 

 reach maturity. We know the vast broods that many insects 

 produce, we have seen a nettle black with the caterpillars of a 

 single butterfly, or a carcass pullulating with the maggots of 

 one blow-fly. Although amongst the higher animals we count 

 large families by sixes and tens, instead of by hundreds and thousands 

 or millions, we know the amazing fertility of many small mammals 

 and birds. 



To produce a large family, making little provision for it, is a 

 wasteful and improvident method of maintaining the species. To 

 limit the number of the young, to lavish on them parental care and 

 not to throw them on their own resources until they are well fitted 

 to make a brave fight against the troubles of the world, are surer 

 means of maintaining the numbers of the species and enabling it 

 to reach a higher level of efficiency. Devices of this kind have been 

 adopted in almost every group of the animal kingdom, but become 

 more universal and more complete as the scale of life is ascended. 

 Not only are the numbers in the family reduced, but the period of 

 youth becomes longer. The protected young are no longer at 

 once absorbed by the immediate problems of life, by the struggle 

 for mere existence. They form in each division of the animal 

 kingdom a kind of aristocracy with leisure for education and training, 

 and with the- opportunity of modifying instinct by practice. The 

 word family in their case acquires a new and real meaning. It no 

 longer is a name simply for the offspring of a single pair of parents, 

 but comes to imply an association of brothers and sisters, of young 

 and parents living together in a new relation, not merely temporarily 

 united by the attraction of sex, but forced to live together in some 

 kind of harmony, with some degree of mutual toleration. The 

 appearance of the family provides opportunity for developing the 

 social habits which are the foundation of the higher sides of 

 mental and emotional life. Co-operation, friendship and love 

 which is not sexual attraction find their first beginnings in limitation 

 of the numbers of the young and in the association of young and 

 old in the family tie. 



In the lower animals the limitation of the numbers of the young 

 and the institution of parental care are often associated with 



