CHROMOSOME STUDIES IN TETTIGID/E. 215 



perpendicular position in the metaphase to the parallel position 

 in the anaphase would indicate a telomitic fiber attachment. 

 In the late anaphase and early telophase the chromatin material 

 begins to take on a granular appearance before the chromosomes 

 have formed into a spireme (Fig. 13). In fact the cell has 

 completed its division before there has been much reconstruction 

 of the chromatin material. 



(a) Chromosomes of CC. Figures 3, 4 and 5 are metaphase 

 plates, polar view, of CC spermatogonial cells. Four of the 

 thirteen chromosomes are decidedly larger than the others. The 

 six smallest chromosomes are,,somewhat narrower at the proximal 

 end than at the distal end. The third pair, marked 3 in these 

 figures, are distinctly pointed at the proximal end, but there is no 

 indication of a bend or hook on this pointed end. The X-chromo- 

 some is more ovoid and when lying in certain positions shows a 

 slight constriction in the middle. Figure 3 shows one of the 

 larger chromosomes split at its distal end. This must be a 

 precocious division, as it was not observed in any of the hundreds 

 of other cells examined. Often one of the chromosomes is 

 observed in the center of the spindle (Fig. 4), or the proximal 

 end may be near the center (Fig. 5). 



(&) Chromosomes of BB. In general the arrangement of the 



chromosomes of BB are like those of CC (Figs. 9-12). There 



are the two large pairs, the three smaller pairs and an intermediate 



pair. The X-chromosome is ovoid with a slight constriction 



near the middle (Fig. 9). There also occurs the crowding of the 



chromosomes toward the center of the spindle. The most evident 



difference between BB and CC is in the third pair, marked 3 in 



all the figures. Not only are these chromosomes pointed at 



their proximal ends, but the point is considerably bent to form 



a definite hook in BB. Sometimes this hook forms an acute 



angle with the other part of the chromosome (Fig. 12), but more 



often the bend is rounded (Fig. 10). The hooked chromosome 



on the left in figure 10 is much smaller than its homologue on 



the right, but this is due to the fact that a portion of its distal 



end was cut off as was also the large chromosomes on either side 



of it. These parts of chromosomes were found in the preceding 



section. 



