32 Nature of the Formative Stimulus 



"But the nucleus can certainly exercise the membrane 

 forming stimulus at an even greater distance." If the 

 nucleus remains united with a whole chain of anucleated 

 bits of cytoplasm "the production of the membrane appears 

 to advance centrifugally and so to commence a little later 

 in the more remote portions of cytoplasm, than in the 

 bits nearer the nucleus." 10 



From these experiments one is inclined to think, this 

 author concludes, "that the production of a cellular 

 membrane required the continuous transmission and 

 cooperation of certain states of motion and vibration 

 which radiate out from cell nuclei or rather owe their 

 origin to the reciprocal action of nucleus and cytoplasm." 



Oscar Hertwig makes in this connection the following 

 remark: "This experiment proves that the stimulus 

 necessary for membrane formation can be transmitted 

 by thin connecting filaments which traverse the septum 

 interposed between two cells. Nothing hinders us then 

 from assuming that some similar transmission goes on 

 in other functional conditions." n 



In these observations of Pfeffer the formation of the 

 membrane goes on independently of the situation and 

 remoteness of the nucleus and of the geometric form of 

 the line of communication which may be straight or 

 curved in any way, and consequently, (and we must keep 

 this especially in mind,) just as though this formation 

 were effected by a specifically stimulating current, passing 



10 Pfeffer: Uber den EinflujS des Zellkerns auf die Blldung der 

 Zellhaut. Berichte liber die Verhandl. der konigl. sachs. Gesellsch. 

 d. Wissensch. zu Leipzig. 1897. P. 507. 



"Oscar Hertwig: Die Zelle und die Gewebe. Zw. Buch, P. 

 40, 41. 



