Tue Hoc Louse 707 
organ; by Miiller (1915), who also showed a number of figures; and by 
Peacock (1916). Nuttall (1917 a:312) described the copulatory apparatus. 
The essential reproductive organs of the female are the paired ovaries 
‘and their oviducts, with the colleterial glands. The remaining parts 
are the uterus and the vagina (Plate LXV, 1). In the hog louse neither 
spermatheca nor bursa copulatrix is present. 
The ovaries are clustered, consisting of five egg tubes on each side, 
and this number seems to be constant in the Siphunculata according to 
the different workers in the group, but the number of egg chambers in 
each tube differs in the various species. Each egg tube consists of a 
terminal filament, a terminal chamber or germarium, and as a rule two 
egg chambers or vitellaria although three are sometimes seen. The 
fine terminal filaments of each ovary of a pair unite, and pass as a single 
filament above the mid-intestine into the fat cells and their tracheoles. 
Graber (1872:159) alone, among the earlier workers, thought that three 
terminal filaments, or vessels as they were then called, passed from each 
egg tube; but, as Gross (1906:350) suggests, he probably confused tracheae 
with terminal threads. The ovaries lie in the abdominal cavity on each 
side of the mid-intestine, and in the region of the sixth abdominal segment 
they fuse to form a short common oviduct on either side. They pass 
into the uterus at the anterior border of the seventh segment after receiving 
the colleterial glands, which are large, trilobed glands with convoluted 
edges. Their anterior lobes, pointing cephalad, lie along each side of 
the mid-intestine under the lateral borders of the ventral abdominal 
muscle plate, and extend to midway between the posterior and anterior 
borders of segment 4; the posterior lobes are shorter, and, pointing caudad, 
extend just within the anterior border of the eighth segment; the lateral 
lobes surround the oviducts and the mid-intestine near the anterior 
border of segment 7. 
The uterus is surrounded by a stout muscular wall which, as Landois 
(1865 a:51) first pointed out, is made up of circular as well as longitudinal 
fibers. After receiving the oviducts it passes caudad through segment 
7 into segment 8, then bends back along itself just into segment 7, where 
it again turns caudad describing a semicircle, so that the point of its passage 
into the short, thin-walled vagina lies on its own spiral. The meaning of 
its length and musculature is revealed in examining specimens having 2 
mature egg in the uterus. It is then a long, straight, and wide tube, 
