710 LAURA FLORENCE 
successive egg chambers are connected by short stalks of epithelial cells, 
apparently a continuation of the follicular epithelium. 
The egg tubes of each side pass into a short oviduct which receives the 
wide conduit of the colleterial gland before passing into the uterus. The 
wall of the oviduct is made up of a thin muscular layer, a fine basement 
membrane, and small epithelial cells with an inner delicate chitinous 
lining; that of the colleterial gland consists of a peritoneal membrane, 
a thin basement membrane, and large columnar epithelial celis with large 
nuclei (Plate LXV, 2). These large epithelial cells secrete the cement 
which glues the eggs to the bristles, and in sections stained with hematoxylin 
and eosin the secretion is seen as a pink, homogeneous, more or less vacuo- 
lated mass, while with iron hematoxylin it appears dark brown or black. 
The uterus receives the oviducts laterally and somewhat posterior to 
its apex. In this region the muscular coat is only moderately developed, 
the epithelium and its basement membrane are clearly seen, and the chi- 
tinous lining is smooth (Plate LXV, 3).. Posterior to the point of entrance 
of the oviducts the wall is thrown into deep folds and the muscular outer 
coat is very highly developed. The epithelial cells are small and no distinct 
cell boundaries are seen. The chitinous lining is thrown into innumerable 
sharp convolutions resembling moderately long, sharp teeth (Plate LXV, 4), 
which, posteriorly in the region of the coil, appear as blunt, rather flattened 
teeth (Plate LXV, 5 and 6). From sections made through a uterus con- 
taining an egg, it appears that these teethlike projections retain their 
form when the uterus is fully expanded. 
The earliest description of the egg of the hog louse is that of Leuckart 
(1855:140-141). He recognized the presence of a third chorionic layer, 
but without sections it was impossible to get a true conception of the 
structure. He figured a piece of the shell, showing it to be provided with 
innumerable canals running perpendicular to the surface of the chorion. 
Strobelt (1882, English trans. 1883:96-97) described briefly the egg of 
Linognathus vituli (Haematopinus tenuirostris), citing Leuckart and 
Landois. The most complete and accurate description is that of Gross 
(1906 : 364-377), who found, in the eggs of Siphunculata (Anoplura) and 
Mallophaga, structures so similar as to indicate close relationship between 
the two groups. Myjéberg (1910:257-262) refers to the work of Gross 
and describes briefly the eggs of several additional species of Siphunculata 
(Anoplura) and Mallophaga. 
