LOGETIC CHARACTER OF GROWTH 



57 



All these facts lead us to believe that the centrosome may re- 

 ceive influences from the cell environment and support the sup- 

 position that the centrosome also during division may be the 

 center by which influences from the environs of the cell are 

 received and activated. 



In metazoa where the cells are heaped together this cannot be 

 proved histologically, but the relations found in several Protozoa 

 seem to support this opinion. The centrosome in a 'dividing' 

 protozoon can have a material relation with the outer world 

 and can readily suffer an influence from the outer world during 

 the partition. 



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Fig. 2 Mitosis in Stypocaulon. The polar radiation is connected with 

 extracellular offshoots which are subject to external influei ees. After Swingle. 



This is demonstrated by the Lophomonadidae 7 and proved 

 also by cases like Stypocaulon (fig. 2), where the centrosomes of 

 a dividing cell are attached to protoplasmic fibers which project 

 into the environment. 



As to the manner in which a cell of the body responds to the 

 influence transmitted by the centrosome, nothing can be said as 

 yet. It would seem, however, that this response is a striving of 

 the body after equilibrium. 



Probably the somatic response will be such that the equilibrium 

 disturbed by the irritation from without is restored; that is, it is 



7 Cf. Hartmann's Protistenstudien, Fischer, Jena, and Doflein's Protozoen- 

 Kunde. 



