ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
57 
determinants, and in tlie distinction between direct and adaptive seasonal 
dimorphism. 
Development of Male Ducts in Silk-Moth.* * * § — Sig. E. Verson, with 
the assistance of E. Bisson, has followed the post-embryonic development 
of the efferent ducts and accessory organs of the male Bombyx mori. 
According to Herold (1815) and Nussbaum (1882) the vasa deferentia 
arise from the posterior strands of the genital organs ( Herold ’s organ), 
while the other parts are derived from the ectodermic epithelium. With 
this general conclusion the author does not agree. In the embryonic 
stages Herold’s organ was not securely demonstrated, nor was the ligament 
of the genital organs traceable to the last segment. In the first larval 
period the solid strands of the testes were seen attached on each side 
to a microscopic pouch of the integument — Herold’s organ. It is an 
invagination on the border-line between the eighth and ninth abdominal 
segments. Just before pupation the following regions are distinguish- 
able : — (a) the testes with their four divisions ; ( b ) the vasa deferentia, 
arising from a hollowing of the testes-strands, and communicating with 
seminal vesicles, accessory glands, and the two ejaculatory ducts ; and 
( c ) Herold’s pouch with four ectodermic knobs, which form the penis 
and its sheath. But in the final elaboration of Herold’s pouch and its 
derivatives, mesoderm elements play an important and intricate part. 
Morphology of the Abdomen in Coleoptera.f — Dr. C. Verhoeff has 
made an elaborate study of the abdomen of Endomychidae, Erotylidae, 
and Languriidae (in the old sense), and of the musculature of the 
copulatory apparatus in Triplax. He describes 22 species, and draws 
42 morphological conclusions, which he thereafter applies to classifi- 
cation. 
Genital Organs of Male Wasp4 — Herr M. H. E. Kluge describes 
the male genital organs of Vespa germanica. The hard parts of the 
copulatory apparatus — spatha, sagittae, cardo, and stipites — are first 
discussed ; then their musculature ; then the ejaculatory duct ; the vasa 
deferentia ; the accessory glands and the testes. Herr Kluge pictures 
the probable action of the different parts of the copulatory process, but 
the act itself eluded his observation. Besides the contributions which 
the paper makes to the descriptive anatomy of insects, it has important 
bearings on classification. For the author emphasises the fact that 
there is great variability even within the species as regards genital 
organs. Therefore too great reliance must not be placed on these in 
distinguishing or establishing species. 
History of a Wasp’s Hest.§ — M. Ch. Janet gives a very careful 
account of the nest of Vespa crabro from its beginning to its completion. 
The first, second, and third grades of nest-development are described 
at length ; the envelopes, the cells, the material used, and the internal 
temperature are all discussed. He has also interesting notes on the 
egg-laying, the larvae, the pupae, the division of labour, the length of 
* Zool. Anzeig., xviii. (1895) pp. 407-11. 
t Arch. f. Naturgsch., lxi. (1895) pp. 213-87 (2 pis.). 
X Tom. cit., pp. 159-98 (1 pi.). 
§ Ex. Mem. Soc. Zool. France, viii. (1895) pp. 1-140 (41 figs.). 
