612 
Mil. LUBBOCK ON THE GENEEATIVE OEGANS, AND 
inch in diameter. At this stage some of the larger yelk-globules were 4 ^ 0 ^^ of 
inch in size, but the majority were much smaller. The Purkinjean vesicle was o ths 
of an inch in size, and the macula was, as usual, single ; it did not, however, appear to 
be a vesicle, but rather, as in Leiohunus, a cloud of particles, without any true surround- 
ing membrane, and more or less compactly arranged. 
The chorion of the egg is no doubt, in all the Phalangiclte, formed by the consolida- 
tion of the outer layer of the viscid part of the yelk ; and as this process is gradual, it 
is impossible to say exactly wdien it begins, or when it is finished. The yelk in the 
mature eggs of Leiobumis and Plialangium is constituted like that of Nemastoina. 
Leuckvet says that in Phalangium, besides the eggs with a simple, homogeneous 
macula, there are some in which it is granular, and others in all intermediate stages. I 
have myself observed the same thing not only in the Phalangidse, but also in many other 
Articulata. The difference arises, however, I believe, from the action of the fluid in 
wiiich the eggs are examined ; and the homogeneous specimens represent the normal 
condition. 
The internal male generative organs of Plialangium (Plate XVII. fig. 45) have been 
quite misunderstood, I think, by every one who has written on the subject. Trevi- 
EAXUS* * * § described the numerous short white tubes which fall into the vas deferens as 
“ Saamengefasse ; ” Tulk also saysf, “The testes are formed by a cluster of elongated, 
narrow and slightly tortuous caecal tubes;” and this view has been generally adopted J. 
Each of these tubes contains a narrow central tube, which gives off on each side nume- 
rous branchlets ; and these branchlets terminate in cluster-like glands. If, therefore, 
they were simplified and shortened very much, they would resemble in structure the 
accessory glands of Chelifer, which are certainly not testes. It would of course be 
unsafe to rely much on this comparison ; but I never found any trace of spermatozoa in 
these tubes, which, on the contrary, contained numerous delicate vesicles about -g-^th of 
an inch in diameter, and with finely granular contents ; the secretion of these tubes, too, 
is, I believe, a fluid. On the other hand, among these short tubes I always found one 
much longer than the rest (Plate XVII. fig. 45, d), and convoluted instead of nearly 
straight. Its internal structure also was entirely different, being without any such small 
branched duct and glands. This I regarded at first as the true testis, especially as at its 
lower end it contained immense numbers of minute spherical bodies, which are the 
spermatozoa. 
There is, however, another large tube («), which was already known to Treviranus§, 
and described by him as the Z-shaped tube. As it occurs only in the males, he presumed 
that it w^as connected with the secretion of the semen, but he was unable to trace its con- 
nexion wfith the other generative organs. The tube lies across the digestive organs, and 
* Vermisclite Schriften, p. 36. t Loc. cit. p. 21. 
X Leuckaet, article “ Zeugung;” Siebold and Staxnius’s ‘Anatomy;’ and Levdig, “ Zum feineren Ban 
der Arthropoden,” Mullee’s Archiv, 1855. 
§ Vermisclite Schriften, p. 37. 
