DID THE ANTHROPOIDS FOUND THE PERMANENT FAMILY? 



Lower mammals whose progeny are able to fend for themselves within a comparatively short 

 time after birth are rarely paired for long. The offspring, being able to take care of them- 

 selves, break away from their parents, and as there is no further dependence on the male 

 for defending the offspring and mother, the parents soon separate, and form other combina- 

 tions the next year. But in the Primates, as the period of dependence of the young becomes 

 lengthened, the dissolution of the family ties is delayed more and more until it eventually is 

 delayed until the recurrence of the next mating season. Thus the union tends to become 

 permanent. Photograph by E. R. Sanborn, New York Zoological Society. (Fig. 4.) 



Large families can only be indulged 

 in by animals that can have a safe 

 retreat in which to rear their numerous 

 young, or by animals sufficiently 

 equipped with weapons to guard them. 



■'Of those animals which, having no 

 nursery to hand, have a reduced litter, 

 there are two distinct classes. The 

 first class, for which we may turn to 

 the horse (as a representative of the 

 Ungulates) for an example, is made up 

 of animals whose roaning life is com- 

 posed of a series of escape- from danger: 

 animals that depend for their safety 

 not upon their retreat into burrows, 

 holes, or any other fastness open to 

 some smaller beasts, but upon the 

 swiftness of their open t'scape. These 

 cannot be successful if the females are 

 handicapped by the disabilities of preg- 

 nancy with large litters, or by th3 

 nursing of helpless offspring. In them 



the number of offspring is reduced, 

 and the usually solitary infant is born 

 singularly mature, so that it may 

 share as soon as possible in the life- 

 saving actis^ities of its species. 



"The solitary young of such animals 

 is born grown up, it can flee at its 

 mother's side within a few liours of its 

 birth. Its period of dependence upon 

 its mother is relatively short, and there 

 is but little infancy, or childhood for 

 such a baby. In the second class come 

 the arboreal animals. There is no 

 natural nu"rery among the tree-tops, 

 and the disabilities of pregnancy with 

 a large litter are felt as keenly in ac- 

 tive tree-climbers as in any class of 

 animals. No doubt nest-building was 

 resorted to as a tempc i-ary expedient 

 in the arboreal stock; and amor g all 

 the arboreal and semi-arboreal animals, 

 derived from many orders, nest-build- 



539 



