10 



the part of soldiers : the relief from anxiety to the remainder of the herd of 

 deer, who can feed in peace while one of their number is on guard to warn 

 his companions of approaching danger; the increased speed in the construction 

 of dams and huts It.v a colony of heavers, where each heaver knows his 

 particular part in the work illustrate the advantages of co-operation for 

 mutual aid through the division of la hour. 



WHAT TIIKSK FACTS TAUGHT HUMAN PARENTS. 



This principle, observed by parents thousands of years ago, impressed 

 upon them the great advantages of caring for their children until they grew 

 up into stalwart sons and daughters, who would aid in the hunt for food. 

 or assist in the defence of the home against the attack of animals or other 

 men: who would guard the flocks or till the land in time of peace; who would 

 cook. brew, and weave: and. finally, who would tend their parents when sick 

 or feeble. This fact is perhaps the most forcible reason for the existence of 

 family life. 



LANDMARK (2). THE GROWTH OF AND NEED FOR PARENTAL CARE. 



If children are to be preserved, in order, later on, to help their parents, 

 intelligent care is most important for their protection during their early 

 years of helplessness. 



Overhanging Kock Shelter. 



Tree Dwellings. 



Where there is no such care, the birth-rate has to be enormous or none 

 of the offspring would survive, so that a species or family would soon die 

 out. Take the herring tribe, for instance, where, so far as is known, no 

 such care exists. Each mother herring must spawn nearly 30.000 eggs a year 

 in order to maintain this species of fish. More than half this enormous 

 number of eggs are never hatched, being devoured by other fish or by sea- 

 birds: and of those which do survive, it is believed that not more than one- 

 tenth attain the ripe age of six months. 



