M 'CLUNG : SPERMATOCYTE DIVISIONS OF THE LOCUSTID.E. 195 



of the elements (figs. 22-'24). Some cysts contain cells that 

 almost invariably exhibit this peculiarity. The lagging chro- 

 mosome is always one of the small ones, but whether the same 

 in each case could not be determined. 



In the telophase, the main interest is centered in the ques- 

 tion as to whether there is a loss of identity of the chromo- 

 somes or not. The evidence afforded by the Locustid cells is 

 strongly in favor of the conception of persisting elements. As 

 is usually the case, I believe, the chromosomes, when not under 

 the active influence of the archoplasm, loosen up, and their 

 homogeneous structure gives way to the granular appearance 

 noticeable in the prophase. Although the chromosomes be- 

 come closely massed and granular, their outlines can usually 

 be distinguished (figs. 23-27) . The accessory chromosome does 

 not change its form and structure at this time (figs. 25, 27). 

 The telophase ends with the ingrowth of the dividing cell-wall, 

 and the second spermatocyte mitotic figure is established with- 

 out any real prophase. Between the two generations it is evi- 

 dent that there exists no such thing as a "rest stage." 



(d) The Second Spermatocytes . 



In the metaphase of the second spermatocyte are formed exact 

 duplicates of the chromosomes seen in the anaphase of the first 

 spermatocyte. These arrange themselves radially in the equa- 

 torial plate, one chromatid immediately above the other, so 

 that the plane separating the halves is at right angles to the 

 spindle axis. Mantle fibers attach to the inner ends of the 

 chromatids at the point at which, in all probability, the fibers 

 of the first spermatoc} T te were connected. I am inclined to re- 

 gard this as true because the opposite ends, during the ana- 

 phase, seemed to be mutually repulsive. 



The spindle itself is small and weak as compared with that 

 of the first spermatocyte, and does not long survive the ana- 

 phase condition. The material composing it, however, persists 

 as the nebenkern of the spermatid. 



A marked difference between the second spermatocytes that 

 contain the accessory chromosome and those which do not is 

 observable. In the metaphase, the element, already longitudi- 

 nally split in the prophase of the first spermatocyte, projects 

 from the equatorial plate for some distance into the cytoplasm. 



