IVm. LUBBOCK ON THE OVA AND PSEUDOVA OF INSECTS, 
357 
fertile ; and as no doubt can exist that these eggs also were capable of fertilization, it 
seems to follow that they must have been produced in the ordinary manner. 
An opinion is prevalent among entomologists in this country, that caterpillars hatched 
from such eggs as these are weak, and can seldom be reared, — as if the vital force was 
indeed sufficient to carry the egg up to the point of hatching, but was by that exertion 
almost exhausted*. 
In the Hymenoptera the process of egg-development very much resembles that of the 
Lepidoptera, but the ovaries differ generally in possessing more numerous egg-tubes, 
each with a fewer number of egg-germs. They differ from the Diptera, and agree with 
the Lepidoptera, Geodephaga, Hydradephaga, and most of the Neuroptera, in having 
each egg-chamber divided transversely into two parts. The vitelligenous cells are gene- 
rally round, as in most of the Neuroptera; but sometimes they are polygonal, as in the 
Diptera and other orders possessing alternate groups of these cells. The nucleus of the 
vitelligenous cells is very indistinct, and can seldom be perceived plainly. In each 
chamber the vitelligenous cells differ considerably in size, being larger and darker towards 
the lowest end. The yelk is generally opake, and not nearly so pale and transparent 
as in some other groups. These circumstances are not favourable to observations on the 
germinal vesicle, which, however, appears to be in most instances (Plate XVII. figs. 2, 
4, 5) a round vesicle, of rather small size in proportion to the size of the egg. 
Plate XVII. figs. 2 and 3, represents two egg-tubes of Cynips lignicola, which I shall 
describe more fully ; and I therefore content myself with mentioning here, that the pro- 
cess in this group offers no essential difference, and that there are no peculiarities in the 
formation of these pseudova, except those which arise from their very peculiar form. 
It is, however, of course possible, that when we shall have obtained a deeper insight 
into the mysterious processes of embryonic development, some differences will be 
detected between these pseudova and ordinary eggs. 
The egg-formation in Clielonus oculator is remarkable, but its peculiarities have been 
much exaggerated by M. Leon Dufoue. According to this eminent anatomist, Chelomis 
possesses neither ovary nor eggs, but instead of them, four matrices containing a great 
number of Ihing embryos, or perhaps nymphs k I was naturally very anxious to 
examine such an extraordinary insect, and by the kindness of Mr. Feedeeick Smith 
was enabled to do so. 
M. Leon Dufoue has correctly described the external form of the generative organs. 
There are four similar matrices, two on each side, and divided by a transverse constric- 
tion into two chambers, the lower chamber being the smaller of the two. The lower 
ends of the four matrices unite into a very short oviduct. The upper ends are gradually 
contracted into a narrow egg-tube. There are therefore four egg-tubes altogether ; they 
are of very considerable length, and each pair is closely united together. At the free 
end they swell into an oblong terminal chamber. M. Leon Dufoue has given also an 
excellent figure of these organs. He denies, however, to these long tubes the name of 
* This idea is confirmed by Leuckabt, Zur Kenntniss, &c. p. 376, and Heeold. 
MDCCCLIX. 3 B 
