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 coUeterial 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 coUeterial gland consists of a peritoneal membrane, 

 a thin basement membrane, and large columnar epithehal cells 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 

 teetli (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 

 (18.55:140-141). 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, Enghsh 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. Mjoberg (1910:257-262) refers to the work of Gross 

 and describes bricfl.y the eggs of several additio:ial species of Siphunculata 

 (Anoplura) and Mallophaga. 



