INTERNAL GENERATIVE ORGANS OF THE FEMALE. 673 
which have usually been regarded as colleterial or glue glands.* 
There are a single pair which open into the sacculus of the 
oviduct by a pair of ducts. These glands lie one on either side 
of the oviduct, embedded in adipose tissue, and each extends 
along the outside of the corresponding tuba, and terminates in 
a cecal extremity which is attached to the ovary. They are 
white, with a pearly lustre, and exhibit a beaded appearance 
due to the projection of the outer surfaces of the cells which 
line them. 
In sections they exhibit a peritoneal coat, and consist ot 
a structureless basement membrane, lined by a single layer of 
large epithelial cells. The lumen of the gland is occupied by 
a granular fluid or semi-fluid substance of a highly coagulable 
character. The granules suspended in this fluid are intensely 
blackened by osmium peroxide. 
The general structure of these glands is similar to that of 
the vas deferens and paragonia of the male; but the epithelial 
elements are much larger, and are irregular in form; the cells 
measure on an average 80 u in diameter, and are from 30 p to 
40 pw thick. 
Many of these cells contain very remarkable spherical cor- 
puscles, usually one in each cell. The corpuscles bear a striking 
tesemblance to the ova of many Mammalia; they exhibit a 
zona pellucida with distinct radial strie, enclosing a granular 
protoplasm, which exhibits a vesicular nucleus with a minute 
highly refractive particle in its interior comparable with the 
well-known germinal spot (Fig. 94). 
Beside these corpuscles, many of the cells also exhibit an 
oblong nucleus, surrounded by a clear area. 
The largest of the contained corpuscles measure 25 » to 
* Colleterial or glue glands are glands which open into the posterior part of the 
genital canal, close to the external orifice, and secrete a viscid fluid by which the 
eggs are varnished or attached to each other, or to leaves, branches, etc. Such glands 
are found largely developed in the Lepidoptera, and resemble the sericterial or sill: 
glands in structure and in the nature of their secretion. There are no colleterial 
glands in the Blow-fly, and the cement with which the eggs are united with each 
other when deposited is probably secreted by the walls of the utero-vaginal tube ; 
the genital fossee are frequently found filled with a similar material, which is ap- 
parently a coagulable albuminous fluid. 
