600 
]\IE. LUBBOCK OK THE GENEEATIVE OEGAKS, AND 
placed between two slips of glass, and these latter were rubbed together, the oil-globules 
ran into one another and took the form of rods, thus showing that they possessed no 
true membrane. 
Ildus . — The most detailed account of the generative organs, and formation of the 
egg, in hdus, is that given by Mr. Newpoet, in his celebrated memoir “ On the Organs 
of Eeproduction and the Development of the Myriapoda Mr. Newpoet correctly 
describes the ovary as consisting of an elongated bag, which “ in the pregnant female is 
smooth and distended with ova that have passed into it from the ovisacs but he figm’es 
and describes these ovisacs as projecting freely from the outer side of the ovary, whereas, 
in fact, in hdus as in Glomeris, the egg-follicles project into the free cavity of the ovary, 
and do not project from its outer surface. Mr. Newpoet was perhaps led into this error 
partly by what he expected to see, but also partly, no doubt, by a misinterpretation of 
what he actually did see. The wall of the ovary is extremely delicate, and at the same 
time so firmly united to innumerable tracheae, and to parts of the fatty tissue, that it is 
almost impossible to detach the organ without injury ; but if the wall is pierced, the 
egg-follicles immediately make their way out of the orifice, and the organ takes on an 
appearance much like that represented in his fig. 5, plate 3. The egg-follicles do not, 
how'ever, clothe the whole inner surface of the ovary, but in this genus, as in Glomeris 
and Polydesmus, are confined to two long ribbon-shaped parts which run along almost 
the whole length of the organ. 
In examining the early stages of the formation of the egg in the follicle, Mr. New- 
poet unfortunately used specimens which had remained for twenty-four hours in recti- 
fied spirits of wine. In consequence, he describes the youngest egg-follicles, which were 
about T^oth of an inch in diameter, as being “ filled with very minute graniform cells 
of a uniform size (about toUcTo^^ of inch), slightly opake, and of a yellow colour.” 
If, however, he had examined in water a freshly killed specimen, he would have found 
these follicles perfectly clear, transparent, and colourless, and the Purkinjean vesicle and 
macula much more conspicuous. In such follicles the yelk always seemed to me to be 
a clear fluid, without any cellular contents at all resembling the minute graniform cells 
described by Mr. Newpoet. The smallest egg-follicles I have observed were about the 
same size as those mentioned by Mr. Newpoet. It is only when they have attained the 
size of about of 9,n inch in length, that they begin to grow dark from the depo- 
sition in their interior of a finely granular yelk. 
When they are -^th of an inch they have become quite opake ; but the yelk-globules 
are still very small, not generally more than g oVo f^ of an inch in diameter. At this 
stage it is not easy to get a good view of the Purkinjean vesicle by crushing the egg, as, 
even if the vesicle is not itself destroyed, the yelk is so sticky that it is difficult to sepa- 
rate it sufficiently. This can, however, generally be effected by tearing the egg open 
carefully with two needles. 
In this manner it can be ascertained that the macula is still single ; but it generally 
* Philosophical Transactions, 1841. 
