GIO 
ME. LUBBOCK ON THE GENEEATIVE OEGANS, AND 
apparently of so mucli importance ; and in all probability, therefore, a true 'vitelline 
vesicle •will be discovered in GeopMlus, though it is certainly not so conspicuous as in 
Arthronomalus. Certainly no such vesicle has yet been noticed in Cryjpto^s^ but it may 
perhaps have been overlooked in that genus also. 
In the largest eggs the yelk completely hid the Purkinjean vesicle, 'which, however, 
became evident on the application of pressure. It had become again homogeneous and 
round, and was about diameter. The macula was single, but often 
vacuolated. 
Acetic acid darkened the yelk and destroyed the macula, as usual. The Purkinjean 
vesicle remained visible by contrast of shade. The full-grown eggs were about ^oW^hs 
of an inch in diameter; and the yelk consisted principally of small oil-globules, not 
larger than 2ir^th of an inch. 
AEACHNIDA. 
Phalangid^. 
Nemastoma himaculatum, Fab. — This pretty little species is common in Kent, under 
stones, logs of wood, &c. When found, it often feigns death ; and its horny skin and 
dark shrivelled appearance may well deceive any unsuspicious observer. It is altogether 
black, excepting two white patches on the back ; and as no other English species is at 
all like it, it has for the physiologist the great merit of being easily identified. 
The general arrangement of the female generative organs is much like that of 
Phalangium Ojgilio^ as described by Teevikanus* and TuLKf. A female dissected in the 
middle of September already contained a few mature eggs, but these became much 
more numerous later in the autumn. 
The external membrane of the ovary is, as usual, structureless ; but on one or two of 
the follicles in an allied species, Phalangium cornutum, I saw bright spots, arranged at 
tolerably regular intervals, and raised a little from the general surface. These were 
probably the last remnants of nuclei, which had disappeared altogether everywhere else. 
The membrane is in places thrown into numerous follicles. Inside the outer membrane 
I found no regular layer of epithelial cells, but a number of nuclei apparently imbedded 
in a homogeneous substance. These nuclei (if I may call them so) are in this species 
unusually plain, round, or elliptical in shape, from of an inch to xmjoth of an 
inch ui length, and with finely granular contents. One of the granules is generally 
larger than the rest, and thus represents a nucleolus. 
It seemed to me that the origin of the egg was as follows. The nucleolus of one of 
the larger nuclei, lying next to the external membrane of the ovary, increased in size, 
while the other granules disappeared; and the nucleus having gradually become a 
Pui’kinjean vesicle, and passed into a follicle, we have thus all the elements of a young 
egg-germ. Whether, however, all the ovarian nuclei are thus in turn developed, or 
whether, as I have sometimes been inclined to think, some of them, after attaining to 
* Vermischte Schriften, p. 34. f Annals and Mag. of Nat. Hist. 1843. 
