ANIMAL AGGREGATIONS AND SOCIAL LIFE 339 



this view would stress the importance of the gang, rather than that 

 of the family, as a preliminary step in the evolution of the social 

 habit. It is important to note that the gang cuts across family lines 

 in its formation, just as do the sleeping collections of male robins, 

 which occur in our parks and orchards during the breeding season. 

 Unfortunately for Spencer's principle, which may be correct in many 

 instances, he limited his theory by a concrete example in ants, where 

 we now know that social development is probably due to an exten- 

 sion of mother-offspring relations; but the easy dismissal of his illus- 

 tration does not necessarily wreck the underlying principle. 



Wheeler (1913a) expressed the usual attitude toward these con- 

 sociations in relation to social origins when, after describing some 

 cases of aggregations in ants, he dismissed them as entirely fortuitous 

 instances, which would occur wherever ants might be abundant and 

 places of refuge scanty; or as the manifestation of highly developed 

 social proclivities, and not of such proclivities in the process of de- 

 velopment. More recently (1930) he said: "Societies really repre- 

 sent very different emergent levels from the associations and have 

 arisen in a different way, though, of course, ancient aggregative 

 or associative proclivities may have been retained by many species 

 and may serve to reinforce their specifically social behavior." Highly 

 developed social life demands well-developed sense organs, central 

 nervous system and muscular apparatus, and in addition to these, 

 according to Wheeler, there must be a development of the family. 

 "All the societies of insects," he says, "are merely single families 



in origin The family origin of the flocks and herds of birds 



and mammals and hordes and tribes of primitive man is also ap- 

 parent; though in these societies the family is open and not closed 

 as in insects, and there is a retention in the flocks, herds and hordes 

 of primitive aggregative or associative tendencies which seem to 

 hark back to the ancestral fish and tadpole stages." 



This attitude may be entirely correct so far as the highly inte- 

 grated societies are concerned; but even in these closely knit organ- 

 izations there is evidence, as has just been recognized, that the 

 numerous aggregations, an account of whose formation, integra- 

 tion, and physiological effects have made up the body of the present 



