S96 TRANSACTIONS AND PROCEEDINGS OF [Sess. lvi. 



nucleolus, i.e., the endonucleolus, brought about by the large 

 amount of directly available food-material. 



It is thus evident that I have not been able to assign 

 definitely any special functions to either the nucleus or 

 the nucleolus, but I believe the hypothesis that the nuclear 

 chromatin-segments and perhaps the nucleoli are organs for 

 the conversion of assimilated material into material directly 

 available for the achromatic elements of the cell, to be not 

 quite erroneous. 



What the function of the paranuclei may be is not known 

 as yet. They play a very important part during the division 

 of the cell, a fact I have already alluded to. For a summary of 

 the recent literature, I must refer the reader to Flemming.* 



Not only during division, but also during fertilisation, the 

 paranuclei have been shown to be active by Fol and Guignard, 

 to whose researches I shall refer when I speak about the 

 phenomena of fertilisation. My assumption that the para- 

 nuclei may be concerned in exerting a trophic influence on 

 the nuclei is based on the phenomena of nuclear division, 

 as I have already explained, but whether they have any 

 other function I am unable to say, and would only warn 

 the reader not to take a teleological view, by considering 

 paranuclei to have been develojjed for the purposes of 

 nuclear division or cell-conjugation. 



To consider the functions of the achromatic parts of a cell 

 would be our next task. 



From my description of the conjugation of the two prim- 

 ordial cells, the reader will have gathered, how, the definite 

 structure of the nucleolus is lost more and more as we 

 approach the act of fertilisation, and, how, after the comple- 

 tion of the act, a new nucleolus results with a structure 

 similar to that of either individual nucleolus before fertilisa- 

 tion, a structure, which I have diagrammatically represented 

 in fig. 48, showing a central, proximal and distal endo- 

 nucleoli and radiating fibres. 



This endonucleolar matter permeating the nucleolus, the 

 nucleus and the cell seems to be the trophic centre for all 

 the organs concerned in assimilation and dissimilation. It is 



* Fleminin;,', Neue Beitrage ■/.. Keiiiitiiiss. d. Zelle, in Aruliiv. f. Mikros. 

 Anatomic, xxxvii. p. 701. 



