Marshall—On the Anatomy of the Dragonfly . 779 
The common opening of the testes is ventral on the ninth 
segment between two valves (tig. 45). It is in the form of a 
longitudinal slit situated on the apex of an elongated papilla 
and can he seen after the valves have been raised. The rather 
thick chitinous covering over the surrounding region of the 
body is interrupted in two places by thinner areas (tig. 45, at 
ends of bracket x), these act as the hinges on which the valves 
move. In many of the specimens examined the seminal vesi¬ 
cles were tilled with sperms. 
Accessory glands were not found in connection with the 
male reproductive organs. The view that the wall of the sem¬ 
inal vesicle has a glandular function, Fenard (11), does not 
seem so probable as to give to the epithelium of the vasa def- 
ferentia this function. A comparison of the structure of the 
wall of these two will show that in the former part (tig. 44) 
the epithelial cells are much smaller than in the latter (fig. 
43). In the vas deferens the cytoplasm may not have the same 
appearance in different parts of the cell, near the outer sur¬ 
face there was noticed in some specimens a darker zone which 
contrasted very clearly with the rest of the cell contents. 
There has been some doubt about the presence, in con¬ 
nection with the vasa defferentia of one or more seminal vesi¬ 
cles. In our specimens there has not only been noted the 
presence of masses of sperms in the vesicles (fig. 45) but the 
great enlargement in the proximal ends of the vasa and the 
change in the histological structure of the wall would point 
to the formation at this place of seminal vesicles. Palmen (16) 
noted this in the dragonflies and, amongst others, in species oi 
Libellula ; he says: “Die beiden Vasa deferentia fand Ich 
vesiculaartig ausgedehnt, wie bei den Ephmeriden; sie legen 
sich im hinteren Korperende in S-fdrmige Biegungen und 
laufen zuletzt, einender median beruhrend, eine kurze Strecke 
nach vorne; hier vereinigen sie sich, und der mittlere Theil 
dringt conisch abwarts gegen die am neunten Sternite belegene 
Geschleehtsoffnung.” 
