zo8 THE POPULAR SCIENCE MONTHLY. 



These cells . . . are independent living beings, the citizens of the 

 state, which constitutes the entire multicellular organism." * 



Again, he declares: "Every cell is an independent organism. 

 ... It performs all the essential functions which the entire or- 

 ganism accomplishes. Every one of these little beings grows and 

 feeds itself independently. It assimilates juices from without, 

 absorbing them from the surrounding fluid ; the naked cells can 

 even take up solid particles at any point of their surface, and 

 therefore eat without using any mouth or stomach. Each sepa- 

 rate cell is also able to reproduce itself and increase. The single 

 cell is also able to move and creep about, if it has room for mo- 

 tion, and is not prevented by a solid covering; from its outer 

 surface it sends forth and draws back again finger-like processes, 

 thereby modifying its form. Finally, the young cell has feeling, 

 and is more or less sensitive." f 



Elsewhere, even more pointedly, he affirms, " The many-celled 

 organism is ordered and constituted on the same principles as the 

 civilized state, in which the several citizens have devoted them- 

 selves to various services directed toward common ends." J 



Both biology and sociology treat of the phenomena of life; 

 both involve psychological as well as merely physical conditions. 

 In the natural order of the sciences the one leads up to the other 

 by an inevitable sequence. There is a similarity in the processes 

 of growth between biological and sociological structures which is 

 noteworthy and most suggestive. Inorganic substances grow by 

 simple accretion, or addition to their bulk. Their growth is in- 

 voluntary, and is chiefly determined by the operation of external 

 forces and conditions. Organic substances, on the contrary, grow 

 by intussusception a process of waste and repair initiated and 

 carried on in the individual cells or structural units throughout 

 the internal constitution of the organism ; and their growth is 

 mainly stimulated by internal, volitional effort. In this respect, 

 as I have elsewhere argued, " the growth of societies resembles 

 that of organic substances ; it is a sort of vital chemistry." * The 

 individual in his relation to society resembles the cell in its rela- 

 tion to the vegetal or animal organism. The death of individ- 

 uals, and the birth and growth of others to fill their places in 

 society, proceed in like manner with the processes of waste and 

 repair in organic structures. 



In the biological structure, however, the attractive forces 

 which bind atoms into cells and cells into an organic unity are 

 molecular and physical. In the sociological structure they are 

 functional and psychical. And herein, I think, lies the explana- 



* Evolution of Man, vol. i, p. 60. f Ibid., p. 131. % Ibid., pp. 149, 150. 



* The Scope and Principles of the Evolution Philosophy, p. 22. 



