GENESIS, HEREDITY, AND VARIATION. 367 



within the constitutions of its units the potentialities of a 

 specific structure, will not develop forthwith the details of 

 that structure. The inherited natures of its units will first 

 show themselves by separating into large groups devoted to 

 strongly-distinguished occupations. The great mass, dispers- 

 ing over promising lands, will make preparations for farming. 

 Another considerable portion, prompted by the general needs, 

 will begin to form a cluster of habitations and a trading 

 centre. Yet a third group, recognizing the demand for wood, 

 alike for agricultural and building purposes, will betake 

 themselves to the adjacent forests. But in no case will the 

 primary assemblage, before these separations,* settle the ar- 

 rangements and actions of each group : it will leave each 

 group to settle them for itself. So, too, after these divisions 

 have arisen. The agricultural division will not as a whole 

 prescribe the doings of its members. Spontaneous segrega- 

 tion will occur : some going to a pastoral region and some to 

 a tract which promises good crops. Nor within each of these 

 bodies will the organization be dictated by the whole. The 

 pastoral group will separate itself into clusters who tend 

 sheep on the hills and clusters who feed cattle on the plains. 

 Meanwhile those who have gravitated towards urban occu- 

 pations will some of them make bricks or quarry stone, while 

 others fall into classes who build walls, classes who prepare 

 fittings, classes who supply furniture. Then along with 

 completion of the houses will go occupation of them by men 

 who bake bread, who ma'ke clothing, who sell liquors, and so 

 on. Thus each great group will go on organizing itself irre- 

 spective of the rest; the sub-groups within each will do the 

 same; and so will the sub-sub-groups. Quite independently 

 of the people on the hills and the plains and in the town, 

 those in the forest will divide spontaneously into parties who 

 cut down trees, parties who trim and saw them, parties who 

 carry away the timbers; while every party forms for itself 

 an organization of " butty " or " boss," and those who work 

 under him. Similarly with the ultimate divisions the 



