214 WM. EEES B. ROBERTSON 



tive. Keeping in mind that in figure 157 the chromosomes are 

 viewed in a direction (nearly parallel with the spindle axis) 

 almost at right angles to that in which they are seen in 179 

 (nearly perpendicular to the spindle axis), it will not be difficult 

 to imagine the results of bringing together in twos, by means 

 of attachments at x, x, the separate chromosomes 7 and 11, 8 

 and 10, 5 and 9 of figure 157. The results would be chromosomes 

 like those in figure 179. It is perhaps necessary to explain 

 further the condition in some chromosomes of figure 179. No. 

 9 is a ring seen edgewise, with the distal region turned toward 

 the observer; no. 5 is seen edgewise, but instead of forming a 

 closed ring (fig. 157) its distal ends are free. The uncombined 

 chromosomes (1, 3, 4, 6) are sufficiently aUke to render their 

 identification in the two figures reasonably certain. It will be 

 observed, however, that there is no chromosome in figure 179 

 corresponding to the no. 2 of figure 157. This is probably 

 due to the removal of that chromosome in an adjacent section, 

 for there is present no other very small chromosome comparable 

 in size with no. 1. 



Figure 180 shows clearly the compound nature of chromosomes 

 5-9 and 7-11 in the fact that at the junctions (x, x) the deeply 

 staining chromatin material is interrupted. 



Figure 181, a late metaphase, shows the compound chromo- 

 somes, 5-9 and 7-11, in final stages of division. They give the 

 familiar E-shaped picture, so often seen in Chorthippus and 

 other species having V-shaped chromosomes, in which one arm 

 of each V is longer than the other. 



Figures 182a, 182b, 182c are lateral views of successive stages 

 of a compound chromosome during the metaphase of the first 

 spermatocyte division. The horizontal arms of the no. 7 part 

 continue to get shortei*. The perpendicular arms of 11, seen 

 in 182a, have disappeared, or do not occur in 182b and 182c. 

 Probably they never existed here; but there is a decrease in the 

 proportionate size of the horizontal part of 11. The vertical 

 ring drawn in figure 183 is probably an 8-10 compound, for the 

 arms of each V are more nearly equal in length (compare with 

 figs. 184, 185). The 8's are in contact by their distal ends only, 



