April 1892.] THE BOTANICAL SOCIETY OF EDINBURGH. 399 



where, therefore, no continuity between the interior of the 

 nucleus and the cell-plasms exists. 



Studying the figures, an explanation has suggested itself 

 to me different from that offered by the author, for although 

 I share with him the opinion that the chromatin-segments 

 are not able to change their position in a cell by themselves, 

 I believe the achromatin of the nucleus (both the achromatin 

 proper and the endonucleolar filaments) to be in direct com- 

 munication with the centrosomes even in the resting-cell, 

 and to have a greater affinity for the archoplasm than the 

 chromatin-segments, and for this reason to aggregate on that 

 side of the nucleus lying next to the archoplasm and its 

 centrosome. Such a massing together of the achromatin must 

 of necessity lead to the chromatin being gradually pushed 

 to that side of the nucleus, away from the centrosome. 



In conclusion, let us study shortly how male and female 

 tendencies are impressed on a cell. 



Minot's and v. Beneden's theories have been aptly called 

 compensation theories by Waldeyer,^ for Minot supposed 

 that all body-cells, and unripe sexual cells, were hermaphro- 

 dite or neutral, and contained two opposite properties, which, 

 in the matured egg and spermatozoon, only occurred singly. 



The female element he called the thelyblast, and the male 

 element the arsenoblast, and any cell containing only either 

 male or female elements, the genoblast. Fertilisation or 

 sexual reproduction was believed to occur when a thelyblast 

 (or female cell) from one source united with an arsenoblast 

 (or male cell) from another source ; the two by their fusion 

 forming a perfect cell, which is called the impregnated 

 ovum. 



Van Beneden suggests that all ordinary body-cells are 

 hermaphrodite, containing two different elements which stand 

 in a sexual contrast to one another, as during the first, as 

 well as subsequent divisions of the fertilised egg, each 

 daughter-cell receives an equal share of male and female 

 chromatin-segments. If, however,* every cell in the body is 

 hermaphrodite, then the sexual cells must also contain both 

 male and female i3rgans, and hence, during some period of 



* W. Wiilileyer, Ueber Kaiyokiuese u. ihre Bezieli. z. d. Befruclituiigsvorg. 

 Arcliiv. f. Mikiosc. Auat. xxxii. 



