226 
MR WALTER RITCHIE ON THE STRUCTURE, BIONOMICS, AND 
Female Reproductive Organs of M. minor. 
The parts may be followed in fig. 19, which shows them as dissected from a 
female minor ready to lay eggs. There are two ovaries, one on each side of the 
abdomen. Each ovary consists of two egg tubes, with a terminal nutritive chamber 
and terminal filament at their apex. The eggs pass from the ovaries to the oviducts, 
which join to form a common portion, the uterus. Associated with the lower portion 
of the uterus we have the bursa copulatrix, receptaculum seminis, accessory gland, 
and slime glands. The bursa copulatrix, along with the lowest part of the uterus, 
forms a structure for the admission of the sperms to the receptaculum seminis ; 
communication is by means of a small duct. An accessory gland produces a 
secretion which mixes with the sperms that are stored in the seminal receptacle. 
On each side of the lowest portion of the uterus (the vagina), and prior to the 
entrance of the bursa copulatrix, is a slime or cement gland. 
Repeated dissection and comparison of the female reproductive organs of minor 
and piniperda yielded no reliable differences. Sometimes it seemed that such a 
difference might be found in the receptaculum seminis (spermatheca), the only 
chitinous part of the female reproductive organs of the two beetles ; but while 
this varied slightly in appearance at different seasons, there was no specific 
differentiating character. 
The variation in appearance of the female reproductive organs may be gathered 
from the following comparisons drawn by Nusslin and Knocke : — 
Unripe. 
The nutritive chamber at the apex of 
the egg tubes is small, and apparently 
seated directly on the oviduct. 
Egg tubes diminutive, short, not prom- 
inent, not separated up into ovarian 
chambers. 
Bursa copulatrix empty. 
Seminal receptacle empty. 
The gland associated with the seminal 
receptacle empty. 
Cement or slime glands empty. 
Ripe. 
Nutritive chambers large. 
Egg tubes long and jointed, so as to 
suggest strings of beads. The egg 
chambers increase in size gradually from 
the nutritive chamber to the oviduct. 
Bursa copulatrix, seminal receptacle, 
gland associated with seminal receptacle 
well filled, and the sperms present. 
Cement or slime glands filled with a 
white secretion and then a citron-yellow 
secretion. 
The above characters proved of very great value in determining the age of the 
minor or piniperda, and in illustration I figure with notes four stages of the female 
