56 



C. U. ARIENS KAPPERS 



Since we have to accept that the fibrillogenetic zone is the part 

 that is first subject to formative (stimulative) influences, it fol- 

 lows that in the embryonic cells the centrosome coincides with 

 the primitive stimulative center. When later the dendrites have 

 arisen, they form the chief receptive apparatus for stimuli, and 

 it is not strange to see the centrosome of the adult cell near the 

 dendrites. 



In the ganglion-cells of the retina O. v.d. Stricht found the 

 centrosome in the dendritic part of the cells and so did N. v.d. 

 Stricht in young spinal ganglion cells still in the bipolar stage. 

 (In adult monopolar ganglion cells they seem to lie often near 



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Fig. 1 Sense cell of the saccus vasculosis of Pleuronectes limanda. After 

 Daminerman. 



the monopolar offshoot). Hatai also found them in the cells of 

 the spinal cord and in the Purkinje cells nearly always in that part 

 of the pericaryon which is directed toward the dendrites (the same 

 seems to prevail in the drawings published by del Rio Hortenga 

 and others). 



This position of the centrosome near the place which receives 

 the influences from the surroundings reminds us of the structure 

 of the spermatozoid where it is attached to the flagellum, and the 

 same applies to ciliated epithelium. 



