On Braula caeca, Nitzsch, a Dipterous Parasite of the Honey Bee. 4>7 
crop, and the other to the chylific ventricle. There are four Malpighian 
tubes, uniting to form a single pair just before entering the small intestine. 
The rectal ampulla is large, conspicuous, and furnished with four typical 
rectal glands, well supplied with trachea. This part of the alimentary canal 
is strongly reminiscent of that of Hippobosca. 
The reproductive organs are shown in Figs. 9 and 10 and need little 
description. There are two ovarian tubules on either side closely applied 
one to the other. The follicles consist of groups of nurse-cells with a 
developing ovum posterior to them ; the nurse-cells get smaller and the ovum 
larger as the egg approaches maturity. There is only one sperm atheca, 
Fig. 11. — Alimentary canal of adult, pv. Proventriculus. cr. Crop. cv. Chylific 
ventricle, mt. Malpighian tubes, rg. Rectal glands, ra. Rectal ampulla. 
tr. Trachea, x 40. 
closely applied to the side of the common ovarian duct — not three as in the 
true muscids. 
The testes are comparatively large sac-like bodies, and there is one pair 
of accessory glands filled with a white granular fluid. The penis is large 
and conspicuous and is armed with a pair of strongly chitinised curved 
spines. 
Our knowledge of the feeding habits of the adult is very scanty, and the 
following, quoted from A. I. Root (4), is perhaps the most authoritative 
statement so far put forward : 
"When the louse wishes to feed it goes to the bee's mouth, where the 
