438 
PEOF. B. T. LOWNE ON THE STETJCTTJEE AND 
vatious beiug in complete accord with those of the above-named 
authors. 
3. With regard to the structure of the so-called gum-glands of 
Musca and probably of other insects, I would submit that a com- 
parison of the description of the gum-glands, as I have given it, 
with the ovary of some Arachnids, Crustacea, and W orms is not 
without interest, 
That such ova are developed within cells and present appear- 
ances exactly similar to those I have described, is pretty evident 
from the figures of the young ovary of Spiders given by Stuhl- 
mann (25), plate ix. figs. 190 and 197, and plate x. figs. 214, 
215, and 216 ; whilst similar appearances are represented by 
Van Beneden (3, 4, and 5) in the germogen of the solid-bodied 
Worms and some Crustaceans. It is true these authors put a 
different interpretation on the relation of the ova to the epi- 
thelium of the germogen ; but the fact remains that their figures 
are such as to show the close resemblance of the germogen in 
these animals and the so-called gum-glands of the fly. 
4. With regard to the morphology of the gum-gland, so long 
as we remain ignorant of the precise manner in which this struc- 
ture and the common oviduct are developed, its morphology will 
remain more or less doubtful, I have already given my reasons 
for the belief that the common oviduct is part of the primitive 
ovary ; and this opinion is generally held. The condition of the 
parts in the Hydrophilidse is an undoubted indicatiou, I think, 
that the gum-glands are merely modified ovarian tubules, and 
have a similar origin from the primitive ovary ; the connexion 
which persists between these glands and the calyx of the ovary in 
the fly is not, I think, unimportaut in this relation. In the 
Hvdrophilidae the gland is comparable with the germ-gland of 
the Crustacea. Compare the figures given by Van Beneden (5) 
and by Stein (24). 
It is true that Palmen (21) states that the appendicular glands 
(the gum-glands and the spermatophorous capsules) have the 
same origin from the ectodermal invagination as the vagina and 
uterus ; but his observations are general, and he believed the 
gum-glauds to open into the uterus. 
5. Supposing my corpuscle to be a germ-ovum, its discharge 
from the cell in which it is developed may be considered an un- 
