OVARIAN OVUM OF CHAETOGNATHS. 



79 



mass constituting the central body of the second kind, and ; the part 

 which follows it disintegrates into granules and are dispersed within 

 the nucleoplasm. In fig. 2 b, the central body has already separated off 

 from the looped chromatic filament, and the outer part of it, which is 

 within the daughter nucleus, is disintegrating into granules. 



By a succession of such direct division, several nuclei with a central 

 body are produced within a cell of the germinal epithelium from a 

 nucleus with the looped chromatic filament (a and e fig. 2, fig. 3). 

 Each of these nuclei then separates with a little protoplasm, as a stalk- 

 cell one after another, and is at last merged into the ovum, the merging 

 beginning from that which is nearest to the ovum. In the ovum b, fig. 

 1, and a, fig. 5, the upper stalk-cell is fusing with the ovum and in c, 

 fig. ] and fig. 8, we see half disintegrating nuclei as remains of the fused 

 stalk-cells. But the nucleus with the looped chromatic filament goes 

 on dividing and producing daughter nuclei indefinitely. After a certain 

 number of division, it is converted wholly into a nucleus with the 

 central body. Two lower nuclei of a, fig. 2, are in their last division. 

 The chromatic filament being stretched equally into two nuclei after 

 the completion of division, two similar nuclei with the central body will 

 be produced. The central body is, in this case, produced from the 

 central part of the equally divided chromatic mass, the outer part of it 

 being disintegrated into the granules. 



The nucleus with the central body may also divide amitotically. 

 The separation of the central body is followed by the constriction of the 

 nucleus in a manner similar to the amitotic division of nucleolated nu- 

 clei as described by various authors (d, e, fig. 2). 



Besides these amitotic division which results in the formation of 

 equal sized daughter nuclei, the nucleus of both kinds may divide un- 

 equally in size and produce one or more small fragments (b, c, fig. 2). 

 It is not rare to find a number of these fragments at the base of a nu- 

 cleus with the looped chromatic filament. 



Thus the nuclei of the cells in the germinal epithelium multiply by 

 direct division and separate as stalk-cells. These are one after another 



