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that their number in the gametophyte would hence be six. We did 

 in fact, always find six chromosomes in the cells of the antheridium 

 and in those of the female plants. 



When the antheridia have arrived at the end of their development, 

 the chromosomes assume a different appearance. At first they are, 

 relatively to their length, fairly thick rodlets. At the last but one 

 division, however, they have the same length, but become much 

 thinner and are no longer so smooth. At this stage six chromosomes 

 can always still be clearly observed. At the last division, and there- 

 fore immediately before the actual formation of the spermatozoids, 

 three of the six chromosomes go to one pole and three to the other pole. 



The nuclei of the spermatozoids therefore do not contain six, but 

 three chromosomes, i. e. a quarter of the number contained in the 

 nuclei of the vegetative generation. 



The cells, in which the reducing division has taken place, and 

 which therefore are about to develop into spermatozoids, may be 

 recognized by their almost invisible cell wall and by their beginning 

 to round themselves off. The nucleus lias again a central mass of 

 chromatin, which is, however, appreciably smaller than that in the 

 younger cells. 



This mass again extrudes a chromatin granule in the usual manner 

 which travels to the periphery and then emerges from the nucleus. 

 The corpuscle arises therefore in the same way as the centrosomc 

 in the cells undergoing division. It does not, however, divide hut 

 goes at once to the periphery of the cell. Meanwhile a piece is 

 again separated from the mass of chromatin in the nucleus, and this 

 time the part separated off is so large, that it is often almost equal 

 to the remainder. At first the two portions remain connected, but 

 afterwards they become completely separated and finally the part 

 of the chromatin which lias been split off, wanders out of the nucleus. 



Ikeno also describes in the changed spermatids of Marchantia the 

 occurrence of a chromatin body by the side of the nucleus, when 

 the centrosome has already quite reached the periphery. 



Where it comes from, he does not know, nor what subsequently 

 happens to it; he only says that the organ disappears again later 

 and calls it "chiomatoi'de Nebenkörper", which name we may retain. 



Having arrived outside the nucleus, if changes its shape in Poly- 

 trichum and extends itself to a bent rodlet. This rodlet grows -further, 

 till at last it becomes a closed circular body. Afterwards it again 

 becomes indistinct and in subsequent stages it can only be seen as 

 a doited ring, which finally disappears completely. We have not 

 been able to discover anything about the significance of this body. 



