ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
31 
Sting of Ants.* — M. Charles Janet describes in Myrmicinac an 
apparatus adapted to close the poison reservoir, and gives a detailed 
account of the mechanism of stinging. 
Respiratory System of the Larvae of Entomophagous Hymeno- 
ptera.f — L. G. Seurat has studied the disposition of the tracheae in 
Braconidae, Chalcididae, and Ichneumonidae, and finds that while the 
fundamental plan is the same throughout, there are minor differences 
which make it possible to establish distinctive characters between the 
larvae of different families. This may be of service in the identification 
of larval forms, usually so difficult. 
Alkaline Reaction of Ants’ Nests. f — M. Charles Janet points out 
that in the chambers and galleries of Solenopsis fugax and other ants 
the reaction is markedly alkaline. This is due to the secretion of the 
integumentary glands, the function of which may be to neutralise the 
acidity of the poisonous secretion. This is probably the special use of 
the accessory (alkaline) gland beside the poison-gland ; it will serve to 
neutralise the small quantity of poison which may remain about the 
delicate and slightly chitinous region surrounding the sting and the 
anus. 
In the same paper the ingenious author notes that workers of Formica 
rufa decapitated by him in his search for the Widbditis parasitic in the 
head, survived in a moist chamber for several days, — three for two days, 
one for three, two for five, one for seven, two for nine, one for nineteen. 
Structure of the Testis in Silk-Moth.§ — Prof. A. Tichomirow de- 
scribes the testis as consisting of connective tissue stroma and sperm- 
cells. The stroma forms (1) a sharply defined sheath to the testis, with 
three septa of looser connective tissue ; and (2) a delicate network of 
connective tissue bridges which traverse the cavity of the chambers 
(intermediate tissue). At some places these bridges may become rich 
in plasma (“ stcirlz plasmatisch ”) ; and this is always the case above each 
of the four chambers into which the testis is divided, thus giving rise 
to “ Yerson’s cell.” Later on, when the spermatocysts begin to mature, 
one of the connective tissue corpuscles of the cyst membrane undergoes 
a similar change, and assumes the role of Sertoli’s cell. 
Monograph on the Parasitic Larva of Thrixion Halidayanum.|| — 
J. Pantel describes at great length the external characters, the structure, 
and the habits of this - rare larva parasitic in the females of Leptynia 
hispanica , one of the Orthoptera. The summary alone occupies over ten 
of the sumptuous pages of La Cellule. 
New Parasite of Bats.1T — Herr P. Speiser describes Poly denes talpa 
sp. n., the sixth species of this genus, from Megaderma spasma. The 
specific title refers to the mole-like outline of the head. 
Wings of Insects.** — Messrs. J. H. Comstock and J. G. Needham 
conclude their discussion of the specialisation of insect wings by reduction 
* Comptes Rendus, cxxvii. (1898) pp. 638-41 (15 figs.). 
t Tom. cit., pp. 636-8. J Tom. cit., pp. 130-3. 
§ Zool. Anzeig., xxi. (1898) pp. 623-30 (5 figs.). 
|| La Cellule, xv. (1898) pp. 7-290 (6 pis.). 
If Zool. Anzeig., xxi. (1898) pp. 613-5 (1 fig.). 
** Amer. Nat., xxxii. (1898) pp. 561-5 (3 figs.). Cf. this Journal, 1898, p. 626. 
