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XXV. Xotes on the Genemtwe Organs, and on the Formation of the Egg in the Annulosa. 
By John Lubbock, Esq., F.R.S. 
Eeceived February 5, — Eead February 21, 1861. 
Mteiapods. 
Theough the labours of Beandt, Fabee, Neifpoet, Stein, Teevieanus, and other eminent 
naturalists, we are tolerably well acquainted with the anatomy of the generative organs 
in the Myriapods ; but these observers have occupied themselves principally with the 
arrangement and forms of the organs, and have not paid much attention to the different 
stages of egg-development, nor to the relation in which the young egg stands with refer- 
ence to the surrounding tissues. This relation is indeed very curious, and seems to have 
been generally misunderstood. It is well known that the Myriapods have not long 
egg-tubes, as is the case with most insects, but that each egg arises in a separate follicle. 
It was, however, natural to suppose that this follicle held the same position with refer- 
ence to the ovar}' as the very similar egg-follicles of certain insects, as, for instance, of 
Coccus. This, however, is by no means the case. In Plate XVII. fig. B, I have given a 
diagrammatic section of the ovary of Coccus, with a single egg-follicle {a), the vitellige- 
nous cells being represented at h, and the Purkinjean vesicle at c. 
If, now, we compare with this a similar diagram of the ovary in Glomeris (Plate XVII. 
fig. A), also with a single egg-follicle, we shall see that this latter is very much alike in both 
cases — the shape of the egg-follicle («), the Purkinjean vesicle (c), and the vitelligenous 
bodies (v) being very similar ; but whereas in Coccus and in all insects the egg-follicle 
projects /row the ovary, in Glomeris and the other Myriapods, so far as my observations 
go, the follicle projects into the ovary. If, therefore, we consider the ovary as consist- 
ing of an outer membrane [d) and an inner epithelial layer [e), it would appear that 
while the egg in the Myriapods arises between these two layers, in the insects it 
originates on the inner side of both. 
This difference appears to me to be very important, and, as will be mentioned under 
the head of lulus, escaped the attention of our great anatomist Newpoet, and led him 
to give an erroneous description of the ovary in that genus. I have chosen to compare 
Glomeris with Coccus in the above-mentioned diagrams, because the vitelligenous bodies 
make the resemblance of, and at the same time the difference between, these two 
genera more striking. If, however, we compare with them a similar diagram of the 
ovary of Phalangium (Plate XVII. fig. C), we shall see, not only that the vitelligenous 
bodies are absent, but that the egg-follicle differs equally from that of the insect on the 
one hand, and that of the Myriapod on the other. The egg-follicle projects /row the 
MDCCCLXI. 4 M 
