312 C. E. MCCLUNG. 



of the accessory and the half of the tetrad, very much resembles 

 the ordinary chromatin elements of the prophase, being, as it is, 

 tetrad in character. Here as always, however, the accessory 

 remains homogeneous while the associated chromosome becomes 

 granular like its fellows. With the establishment of the second 

 spermatocyte mitotic figure this oddly constituted tetrad takes its 

 place in the equatorial plate with the mantle fiber attached at the 

 point where the accessory chromosome is joined to the other one. 

 Since the accessory is the shorter the fiber is not inserted at the 

 middle of the chromatin rod but slight'y to one side. The normal 

 form and position of the chromosomes of the second spermatocyte 

 in metaphase is that of a split rod pointing radially away from the 

 axis of the spindle with the chromatids placed one above the other 

 in the plane of the spindle axis. While all of the remaining 

 chromosomes of Hesperotettix are thus arranged, the accessory 

 chromosome and its mate are bent upon each other so as to 

 present an angle to the spindle. It thus happens that in the 

 anaphase there is apparent a heterotypical division of the multiple 

 chromosome in which the resulting V-shaped loops each have 

 one arm shorter than the other. It is now evident that the chro- 

 mosome associated with the accessory has taken part in a hetero- 

 typical division in the spermatogonia and in the second spermato- 

 cyte, and in each case the plane of division corresponds to the 

 original longitudinal cleft of the spireme thread. Because of the 

 early association between the accessory and the tetrad there can 

 be no doubt regarding the planes of division in the hexad. 



I have not as yet attempted to work out in detail the specific 

 characters of the Hesperotettix chromosomes, although I have 

 that in mind for an early investigation. But even in the pre- 

 liminary study here presented there have become apparent specific 

 differences in the first spermatocytes which seem to be constant 

 and which I will briefly notice. The description given above 

 is based upon Hesperotettix speciosits, a form of larger size than 

 the others and with strongly marked characters. Besides this 

 there are in the same habitat two other species that are somewhat 

 common and which are plainly different from H. speciosns but 

 resemble each other in size and general appearance. This close 

 resemblance caused my collectors to confuse the material from 



