The Organism and Its Cells 161 



from the old elcmentalist form of reasoning. 



The name of E. B. Wilson was coupled with that of Whit- 

 man in my general introductory remarks on the appearance 

 in modern biology of the conception of the organism as a 

 whole. We will now examine in some detail tliis authority's 

 views concerning the cell in development. Discussing the so- 

 called Mosaic theory of development in 1893 Wilson said, 

 ''I will here point out one all-important point which is 

 definitely established by the work of Driesch and other ex- 

 perimentalists, and which is accepted by all opponents of 

 the mosaic theory, namely, that the cell cannot be regarded 

 as an isolated and independent unit. The only unity is that 

 of the entire organism, and as long as its cells remain in 

 continuity they are to be regarded not as morphological 

 individuals, but as specialized centres of action into which 

 the living body resolves itself, and by means of which the 

 physiological division of labor is effected." ^^ 



After referring to Schwann's having drawn "the con- 

 clusion that the life of the organism is essentially a com- 

 posite ; that each cell has its independent life ; and that the 

 whole organism subsists only by means of the reciprocal 

 action of the single elementary parts," Wilson says : "It is, 

 however, becoming more and more clearly apparent that this 

 conception expresses only a part of the truth, and that 

 Schwann went too far in denying the influence of the or- 

 ganism u})on the local activities of the cells. It would, of 

 course, be absurd to maintain that the whole can consist 

 of more than the sum of the parts. Yet, as far as growth 

 and development are concerned, it has now been clearly 

 demonstrated that only in a limited sense can the cells be 

 regarded as co-operating units. They are rather local 

 centres of a formative power pervading the growing mass 

 as a whole, and the physiological autonomy of the individual 

 cell falls into the background. Broadly viewed, therefore, 

 the life of the multicellular organism is to be conceived as a 



