74 



bulletin: museum of comparative zoology. 



again, the chromosomes are evidently in pairs. Next in size to the 

 three largest pairs (1, 2, 3) is an unpaired chromosome (4), the mono- 

 some. Then in a series of diminishing sizes we have the pairs 5, 6, 7, 

 8, 9, 10. As in the preceding species, there are two pairs, 11 and 12, 



G. 



8^~ 



Fig. F. — Polar view, metaphase of spermatogonium in Hippiscus iuberculatus 



sliowing autosome pairs. X 1450. 

 Fig. G. — Polar view, metaphase of spermatogonium of Melanoplus femoratus 



showing autosome pairs. X 1450. 

 Figs. Ha, Hb, — Successive sections of oogonium of Hippiscus iuberculatus 



during prophase showing autosome pairs. X 1450. 



which are much smaller than the rest. Figures Ha and Hb represent 

 two successive sections of an oogonium of this species in the late pro- 

 phase. Here there are plainly twenty-four chromosomes, all of which 

 can be readily arranged in twelve pairs. A comparison of these with 

 Figure F will show that these pairs correspond exactly with those of 



