THE 'NON-CELLULAR' TYPE 55 



have also followed out the gradual loss of 

 motility, and the coherence of the individual 

 cells, for a period of their lives at any rate. 

 We have furthermore recognised the fact 

 that there exists a mutual influence, of a 

 material kind, which leads to the co-ordination 

 of the cells of a colony in such a way as to 

 produce, not a mere congeries of separate 

 entities, but an organism. In other words, we 

 have traced the gradual curtailment of the 

 individuality characteristic of the primitive 

 cells, and have witnessed the corresponding 

 transference of it to the cell colony as a whole. 

 This transference of individuality is intimately 

 connected with physiological correlation, 

 which is doubtless exerted through functional 

 and material agencies largely by modifica- 

 tions in the nutritive processes with the 

 result that each cell unit is intimately affected 

 by what is going on in its neighbours, as well 

 as in other and more remote regions of the 

 organism; the final result is that the cell 

 tends to become more definite and circum- 

 scribed in form, and more limited and special- 

 ised in function. To put it a little differently, 

 the efficiency of the colonial organism is 

 purchased at the price of the individual 

 independence of the units which compose it. 

 If, however, we ask the question, What 

 advantage do the cells gain by this union ? 

 the answer is not easy to give. The uni- 

 cellular forms succeed very well, and they live 

 in the same sort of environment as the multi- 



