240 WM. REES B. ROBERTSON 



longitudinal rods lying side by side in his 'biseriale Anordnung' 

 (see Matscheck's text figs. 10, 11,. etc.). Such transversely 

 segmented, four-strand, rod chromosomes of copepods corre- 

 spond to the transversely segmented V compounds of Chor- 

 thippus (my figs. 164, 165, 168, 176, etc.). In anaphase the spindle 

 fibers, evidently attached to the constricted part in the middle, 

 make the daughter chromosomes appear V-shaped (his text 

 figs. 7, 8), as in Chorthippus. In synapsis they remain in contact 

 longer than the intermediate parts of the chromosomes. I be- 

 lieve, in short, that the "chromosomes in biserial arrangement" 

 (Haecker and Matscheck) are indeed compound chromosomes. 



Those investigators of insects who have worked upon species 

 of Stenobothrus and of the Locustidae have found a few of these 

 chromosomes. Stevens ('12) shows for Ceuthophilus two chro- 

 mosomes (fig. 29) similar to my figure 176, but, as usual, has mis- 

 represented the relation of the middle to the terminal rings at 

 the points of crossing (figs. 30a, 30b). In the metaphase and 

 anaphase (figs. 31-33) there are evidently V's with unequal 

 arms separating from each other. One of them shows the E- 

 appearance. In Stenobothrus (Chorthippus) de Sinety ('01) 

 has shown, but again wrongly interpreted (figs. 122, 123), these 

 compound chromosomes. Compare b in his figure 124 with my 

 no. 8-10 chromosome in figure 178; also a in figure 125 with 

 my figure 182c. The latter he has illustrated incorrectly, I 

 believe. Davis ('08, fig. 87) gives two chromosomes similar to 

 my no. 7-11 in figure 174. He is, like others, wrong in showing 

 the loops of the middle ring crossing each other rather than pass- 

 ing into each loop of the terminal rings. What I have found 

 in this species (figs. 181-183) is almost identical with his figures 

 88, 91. The criticisms I have made of Davis's figures applies 

 to those of Gerard ('09, figs. 37-44, S. biguttullus) and of Meek 

 ('11, figs. 10, 11, 14-16, 18; '12, figs. 276-289) in S. viridulus. 



In the works of Baumgartner ('04) and Payne ('12) on Gryl- 

 lidae, which exhibit a large number of V-chromosomes, the pe- 

 culiar perpendicular rings of their metaphases probably result 

 from the separation of the members of V pairs. Nowlin ('06) 

 deals in Coptocycla with many pairs of V-shaped chromosomes. 



