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- 
