4 W. J. BAUMGARTXER. 



Voinov (32) to describe the two closely approximated bodies as 

 a double nucleinic body " corps nucleinien double." (For a 

 criticism see in "Discussion" below.) I could note no differ- 

 ence in the size of the nucleolus that was constant. In the pro- 

 phase of the first spermatocyte division the nucleolus gradually 

 loses its ability to stain and disappears completely while the 

 chromosomes are forming. 



The accessory chromosome can be distinguished from the ordi- 

 nary chromosomes in late prophase by its denser stain and 

 smooth outline. But as the chromatin concentrates more and 

 more in the latter we must find other criteria. The position no 

 longer answers, as many of the ordinary chromosomes now come 

 to lie in or near the periphery of the nucleus, and in a few cases 

 it becomes something of a puzzle to know which is the accessory. 

 But about this time the shape assumed by the latter becomes a 

 mark of distinction from the others. As shown in Figs. 12, 13, 

 15, 17, and 20 it assumes a sausage shape and keeps it all 

 through the first spermatocyte division. As the spindle is 

 formed and the other chromosomes are drawn toward the equa- 

 torial plate, the accessory may be in any position whatever 

 within the nucleus. McClung (18) says it appears nearer one 

 pole. It does very frequently. It may be within the spindle 

 or out in the cytoplasm as Sinety (28) thought he found it in 

 other Orthoptera. But it may lie even in the equatorial plate 

 where I have seen it in several cases. Either the open or the 

 curved side of " the sausage " may point toward its nearer pole. 

 In metaphase and anaphase it is usually the curved side. 



As the other chromosomes move to the poles the accessory 

 also seems to be drawn towards its nearer pole but it is again a 

 laggard (Fig. 23). It does not divide but passes entire to one 

 of the poles as Sinety has already indicated for Gryllus ccunpcstris 

 and he and McClung have described it in Locustids and Phas- 

 mids. I found a few cases where the accessory was left in the 

 plane of cleavage between the two daughter cells. Here it was 

 divided into two equal parts as seen in several cases (Fig. 22), 

 and unequal in one case. In one case the accessory was just in 

 the center between two poles and showed constrictions at its cen- 

 ter (Fig. 21). In these cases I believe the accessory happened 



