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.” ?° 
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.” 14 
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 
Pfeffer: Uber den Einflug des Zellkerns auf die Bildung der 
Zellhaut. Berichte iiber die Verhandl. der kGnigl. sachs. Gesellsch. 
d. Wissensch. zu Leipzig. 1897. P. 507. 
“Oscar Hertwig: Die Zelle und die Gewebe. Zw. Buch, P. 
40, 41. 
