100 Proceedmgs of Royal Society of Edinburgh. [sess. 
trusion and retraction ; but the hooked penis in Noctua, although 
serving to retain the female, appears to be so constructed as to be 
broken in coition, consequently, that act cannot be repeated. 
The semen appears to be transferred to the copulatory organ by 
a strong inflection of the posterior end of the abdomen, and it is 
then discharged into the vagina of the female. 
The spermatozoa (fig. 9) are filiform, with rod-shaped heads and 
long flagella. 
The Female Organ. 
The ovaries (fig. 1, a) consist of eight tubes, four of which lie 
coiled on each side of the body. Their slender tips end in sus- 
pensory ligments, all eight of which unite together immediately 
beneath the dorsal vessel. At the basal ends the ovaries of each 
side of the body unite into a uterine chamber (fig. 1, 5), the short 
oviducts from Avhich unite into a single oviduct, which passes 
through the eighth and ninth segments, and opens beneath the 
lateral flaps of the latter beneath the anal aperture. 
Two colleterial glands, which have the function of secreting the 
egg-shell and the cement by which the moth fixes the ova in place 
when laid, open into the oviduct. The anterior colleterial gland 
(fig. 1, c) is single ; while the posterior (fig. 1, c) is a pair of glands 
with a single duct, or rather with ducts which ultimately unite 
into a single one. Both of these glands consist of long, convoluted, 
coecal tubes, with oval-shaped dilatations near the base ; and these 
are followed by another dilatation. 
At the base of the eighth segment, on the ventral side, opens the 
vagina (fig. 1, d), the opening of which is distinct from that of the 
oviduct. It may be remarked, en passant^ that in most Lepidoptera 
the vagina and the oviduct open by a common duct. The vagina 
of Noctua is a long canal with a smooth, stout cuticula, which passes 
into a large pyriform copulatory sac (fig. 1, e). The walls of this 
sac are very thick, and consist of a powerful muscular layer (fig. 
4, a), within which is an epithelium layer (fig. 4, 6), which gives 
rises to a thick cuticula (fig. 4, c). This cuticula lies in heavy 
folds (fig. 2), which have a general longitudinal direction, but with 
various curves and anastomosing branches. It is covered with little 
processes (cuticular spines), which are thicker near the base of the 
