130 KANSAS UNIVERSITY QUARTERLY. 



herewith. My thanks are also due to Prof. S. J. Hunter, for assist- 

 ance in the determination of the insects from which the material was 

 taken. 



MATERIAL. 



Brachy-stola magna, commonly known as the "lubber grasshopper 

 of the plains," is one of the largest known species of locust. It is 

 clumsy and ungainly, having powerfully developed legs and the most 

 rudimentary wings. 



In distribution, the insect is general — though more or less rare — 

 over all the western plains. The adults put in their appearance about, 

 the first of July, and at this time the testes are found to contain 

 spermatogonia, spermatocytes, spermatids, and spermatozoa, in order, 

 from the blind ends of the follicles to the I'as deferens. 



The testis is unpaired. The follicles, of which there is a large 

 number, are comparatively short and thick, and do not lie approxi- 

 mately parallel to one another and to the long axis of the animal, as 

 is the case in many other AcrididfTe, but project upward and Imck- 

 ward from the rliacis to which they are attached, and diverge strongly 

 from one another. 



The young testis is smaller than the mature one (which attains tlio 

 size of a large pea), is pure white in color, and of a firm consistency. 

 In the older organs the white color gives way to a reddish yellow, 

 and the testis becomes soft. 



The proximal portion of each follicle, as it is evacuated of sperma- 

 tozoa, becomes constricted, and thus the follicle loses its earlier 

 cylindrical form. 



Of the origin of the acridian testis nothing has bi-en written, and, 

 as my material was too old for a thorough study of the subject, I will 

 leave the cjuestion until a later time. However, in the testes of 

 nymphs of Arph'uf, taken about the time of the first molt. I havo 

 seen a longitudinal rhacis having follicles attached to it, as in 

 the adult organ, both rhacis and follicles being so small that in a 

 longisection not more than four of the primary spermatogonia with 

 which they are filled could be seen abreast; that is, the diameter of 

 the follicle and of the rhacis was about four times that of a cell. The 

 testis of Hrac/n/.sfola probably passes through a similar stage. The 

 primary spermatogonia of these follicles divide as such until the testis 

 has attained a considerable size, when they go over into secondary 

 spermotogonia, as described later, each one at the transition giving ■ 

 rise to a spermatocyst. This change begins at the proximal end of | 

 the follicle and, proceeding fastest along the follicular membrane, | 

 extends as a wave toward the distal end, the riper cysts being forced r 

 toward the ra.s (Jeferens by the growth of those beyond. The small 



