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ROBERT H. BOWEN. 



stricted in this original sense, the term may prove very useful, 

 especially in such a case as the present one. 



To return to the metaphase figure, apparently by the time the 

 spindle is completed the ring of dictyosomes has already begun 

 to spread out, and soon these bodies migrate throughout the 

 space between the centrioles and peripheral to the spindle. At 

 first all semblance of order is lost and the dictyosomes seem to 

 be scattered at random around the spindle. But presently it can 

 be seen that they are migrating toward the poles of the spindle in 

 a very orderly way, and as the equatorial region gradually be- 

 comes clear, they are seen to be collecting in approximately equal 

 groups in the vicinity of the centrioles (Fig. 15). In Euschistus 

 this grouping is always somewhat loose, especially in the large 

 cells, but in Brochymena (Fig. 15) the dictyosomes collect in 

 two very accurate rings encircling the poles of the spindle, and 

 presenting in polar view a most characteristic appearance. 



During this entire process of dictyokinesis 1 the chromosomes 

 retain their position in the metaphase plate, and only when the 

 two groups of dictyosomes have completed their journey toward 

 the centrioles do the chromosomes resume their activity as the 

 anaphase begins. As the cell draws out, the groups of dictyo- 

 somes are also separated, so that for a brief interval the sepa- 

 rating chromosome plates lie in a clear intermediate zone. Soon, 

 however, they overtake and pass through the ring-like groups of 

 dictyosomes and, as the daughter chromosomes complete their 

 movement to the spindle poles, the groups of dictyosomes break 

 up and begin to wander out through the general cytoplasm of the 

 cell, becoming scattered apparently in all directions. During the 

 period just prior to, and following the final anaphase the dictyo- 

 somes seem to undergo a second fragmentation, so that those of 

 the second spermatocytes are markedly smaller in general than 

 were those of the first. The dictyosomes form a belt, rather less 

 definite in contour, around the chromosome plate of the second 

 maturation division, and the process of dictyokinesis is repeated. 

 Indeed, the steps are so similar to those of the first maturation 



i A term employed by Perroncito to denote the division phenomena of the 

 Golgi apparatus. Compare the parallel term, karyokinesis. See especially, 

 Perroncito ('10). 



