882 DARWINIANA. 



the conquerors. The saying that ' a house divided against 

 itself cannot stand,' receives in Nature its flattest contradic- 

 tion. Civil war is here the very instrument of progress ; it 

 brings about the survival of the fittest. Original diiferences in 

 the cell-colonies, however slight, will bring about diflerences 

 of life and action ; the latter, continued through successive 

 generations, will widen the original differences of structure; 

 innumerable species will. thus spring up, branching forth in 

 every direction from the original stock; and the competition 

 of these species among each other for the ground they occupy, 

 or the food they seek, will bring out and develop the powers 

 of the rivals. One chief cause of superiority will lie in the 

 division of labor instituted by each colony ; or, in other words, 

 in the localization of the colony's functions. In the primitive 

 associations (as in the lowest organisms existing now), each cell 

 performed much the same work as its neighbor, and the func- 

 tions necessary to the existence of the whole (alimentation, 

 digestion, respiration, etc.) were exercised by every colonist in 

 his own behalf. Social life, however, acting upon the cells as 

 it acts upon the members of a human family, soon created dif- 

 ferences among them — differences ever deepened by continu- 

 ance, and which, by narrowing the limits of each colonist's ac- 

 tivity, and increasing his dependence on the rest, rendered him 

 fitter for his special task. Each function was thus gradually 

 monopolized ; but it came to be the appanage of a single group 

 of cells, or organ ; and so excellent did this ■ arrangement 

 prove, so greatly were the powers of each commonwealth en- 

 hanced by the division of its labor, that the more organs a 

 colony possessed, the more likely it was to succeed in its strug- 

 gle for life. . . . We shall go no further, for the reader will 

 easily fill out the remainder of the picture for himself. Man is 

 but an immense colony of cells, in which the division of labor, 

 together with the centralization of the nervous system, has 

 reached its highest limit. It is chiefly to this that his superi- 

 ority is due ; a superiority so great, as regards certain functions 

 of the brain, that he may be excused for having denied his 

 humbler relatives, and dreamed that, standing alone in the cen- 

 tre of the universe, sun, moon, and stara, were made for him." 



