442 Mr. Ngw»ronr on the Anatomy and 
error has been committed by M. Pictet in regard to the sexes of Pteronarcys, 
as I shall presently show. | 
The male internal organs are very simple in their character. They consist 
of a pair of testes (fig. 14 x) with long convoluted ducts, and a pair of short 
vesicule seminales (y). These, with the ducts, unite behind the terminal gan- 
glion of the nervous cord in a short vas deferens on each side, which termi- 
nates in a long ductus ejaculatorius and organ of intromission (z). : 
The festes are placed above and on each side of the alimentary canal in the 
fifth, sixth and seventh segments of the abdomen. Each testis (x) is formed 
of a multitude of pear-shaped follicles attached around, and opening into a 
common canal. These follicles (fig. 15) are filled with rounded bodies, which 
line their interior, the proper secretory structures for the production of sper- 
matozoal cells, some of which, of minute size, I have observed at the junction 
of the follicles with the canal. The aggregation of follicles together forms 
an elongated oval testis, which terminates in a long convoluted duct. The 
vesicule seminales (y) are short, thick czecal organs of an opake white colour, 
and folded twice or thrice on themselves. They occupy the posterior part of __ 
the eighth abdominal segment, and are continuous backwards with the vasa 
deferentia on each side, at the point of union of the ducts from the testes. 
The vasa deferentia thus formed pass backwards to the margin of the eighth 
abdominal segment, and then unite laterally and pass to some distance for- 
wards, where they end in a single vessel, a long ductus ejaculatorius, which 
returns backwards to the outlet of the tenth segment to end in the penis (2). 
The object of the great length of this duct, and of the arrangement of the 
organs, seems to be to facilitate the transmission of the male influence at the 
tue of union of the sexes. The long process on the under surface of the 
eighth segment (fig. 16) appears to be elevated and employed by the male as 
an organ of prehension, to grasp and retain the terminal segment of the 
female, the body of the male being reversed during the act, as in the Derma- 
l ptera and Orthoptera. By the elevation of the process of the eighth segment, 
and the elongation of the ninth and tenth segments, the position of the vesi- 
ode and ductus ejaculatorius is altered, and the passage of the male influence 
is then direct and unimpeded. 
~ s: Ictet, however, has mistaken the process in the male for an ovipositor, 
