INTRODUCTION 1 1 



asexually, giving rise to offspring which remain 

 attached to it, the whole forms a colony. All 

 the cells of this colony spring then from one 

 single cell (a fertilized egg cell), and an inter- 

 change of nutriment goes on incessantly among 

 these cells. This is what Spencer designates as 

 a " physiological contract." Societies, on the other 

 hand, consist of units springing from various sources, 

 whose connection is merely mental. It is only in 

 the communities which Tonnies calls " Gemein- 

 schaften" in distinction from societies bound by 

 mental agreement (Gesellschaften), that all the in- 

 dividuals spring from one and the same couple. 



From our point of view, a colony must not be 

 regarded as an intermediate condition between an 

 individual and a society. No known society has 

 passed through a colonial stage, and the members of 

 a colony could not, on separating, become a society. 

 Among the simplest aggregates, all the units are 



und Entwicklungsfdhigkeit kernloser Seeigel-Eier, und ilber the 

 Mogliclikeit ihrer Bastardiruny. Arch. f. Entwicklungsmechanik 

 der Organismen, Bd. ii., pp. 394-443), for instance, has shown 

 that it is possible to fertilize the eggs of Echmoderms, from 

 which the nuclei have been removed, by the spermatozoa of 

 other species of Echinoderms. The egg is a typical cell, an 

 organism, an individual. All its parts are essential to it, and 

 arc incapable of separate existence, at any rate for any length 

 of time ; close physiological bonds unite the component parts, 

 yet it is possible to substitute for an essential part of one 

 individual a part taken from another individual. It may there- 

 fore be concluded that the idea of an organism no longer necessarily 

 implies the idea of continuous functional unity which one was 

 formerly tempted to ascribe to it. 



