Marshall—Reproductive Organs of the Female Moth . 3 
tubules, these are not bound together in any way, but each one 
throughout its entire length is separated from the others. Be¬ 
fore the expulsion of the eggs each tubule is from 70mm. to 
80inm. in length. The number of eggs each contains is not 
constant, thirty-eight being the average in those counted. The 
tour tubules on each side unite to form an oviduct, 1.5 mm. m 
length, and the two oviducts join in the median line to form an 
oviductus communis 2 mm. long. 
Throughout the entire length, from the distal end of the 
tubule to that point where the oviductus communis passes into 
the vagina, the wall is very similar in structure. On the inner 
surface there is a folded chitinous layer, somewhat thinner near 
the distal end. The next layer, the epithelial, has, as such, 
nearly disappeared, and in its place is an empty space contain¬ 
ing a few scattered nuclei each of which shows a few irregular 
chromatin granules. The cytoplasm, which we can assume was 
present when the cells were active, has entirely disappeared. 
Externally each tubule is lined with two muscular layers, an 
inner circular, and an outer longitudinal layer. Throughout 
the entire length of the tubule there is only a very slight, if 
any, difference in the comparative thickness of these two layers 
(Figs. 5 and 6). Sections cut through the distal end and the 
middle of the tubule will show this. 
The oviductus communis shows a slight change from what we 
have just described for the ovarian tubule. The remains of the 
epithelial cells are much more marked, the nuclei appearing at 
fairly regular intervals, and the cell boundaries, while not com¬ 
plete, are present in such a condition as would allow us to limit 
the boundaries of the cells which were earlier present in this 
layer. Both muscular layers show a greater development (Fig. 
7), and while the circular longitudinal layers bear to each other 
the same relative thickness that they did in the tubule, both are 
here very much thicker. In all specimens of Hemileuca exam¬ 
ined the eggs were fully developed, and in most of the moths 
they had been in part or entirely expelled from the body. The 
egg-laying goes on rapidly, and but a short time is needed for 
the expulsion of all the eggs from the body. The only use the 
