334 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Production of Sound by Ants.* — M. C. Janet has made some experi- 
ments with ants which lead him to think that the numerous rugose 
surfaces on the bodies of ants are so placed that two of them can be 
rubbed together on the organs which produce the stridulating sounds of 
the Formicidae ; it is allowed, however, that these rugosities have other 
uses, as those about the articulations seem to hold the body stiff at 
those points. 
Antennary Nerves and Chordotonal Organs in Ants.t — M. C. 
Janet has found chordotonal organs in various regions of the body of 
Ants other than the tibiae. One of the most remarkable accompanies 
the nerves of the antenna, and may be called the pre-antennary organ. 
Another is placed on the prothoracic ganglion. The latter has been 
found in the wasp and bee, but the former appears to be peculiar to ants. 
Hypermetamorphosis of Cantharidin8e4 — M. J. Kiinckel d’Her- 
culais finds that it is under the form of a “pseudo-chrysalis” that 
vesicating Insects with retarded development pass, in a lethargic sleep, 
several summers and several winters. In fact they are encysted like 
Gregarines, many Infusoria and Nematodes ; in this encysted state de- 
velopment is arrested, and life remains latent until the external media 
become favourable. This so-called hypermetamorphosis is, therefore, 
comparable to encystation. 
The author objects to the term pseudo-chrysalis, and proposes to 
replace it by that of hypnotheca , while for the similarly objectionable 
term hypermetamorphosis that of Jiypnodia may be substituted. The 
latter new term may be applied to analogous phenomena of arrest of 
development with encystation, in which there is no histolysis or histo- 
genesis. 
Salivary Glands of Crabronidae.§ — M. Bordas finds that these 
organs, which have never been investigated, consist of five pairs — 
thoracic, supracerebral, mandibular, sublingual, and lingual. He gives 
some details as to the form and structure of each, but offers no general- 
izations. 
Tracheal System of Larval Hymenoptera.|| — M. Bordas appears to 
be the first who has investigated the anatomy of the tracheal system of 
the larvae of Vespidae. He finds that it consists of two long lateral and 
parallel cylinders, which give off transversely numerous ramifications ; 
these are united anteriorly by a large trunk, and posteriorly by two 
branches of unequal size, which form a circumrectal ring. 
Formation of Silk.^j — Prof. G. Gilson finds that the silk-producing 
apparatus of the larvae of Phryganidae is very similar to that of the larvae 
of Lepidoptera, and that the silk is formed in the same way. The 
chitinous tube of the anterior portion of the glandular tube forms an 
interesting object for the study of the genesis and signification of the 
cellular membrane. As the origin and cytoplasmic nature of this part 
of the cell are evident, it is impossible to consider the cellular membrane 
* Eev. Scient., 1894. See Amer. Natural., xxviii. (1894) pp. 270 and 1. 
f Comptes Rendus, cxviii. (1894) pp. 814-7 (2 figs.). 
I Op. cit., cxviii. (1893) pp. 360-3. § Tom. cit., pp. 363-5. 
|| Op. cit., cxviii. (1894) pp. 664-6. H La Cellule, x. (1894) pp. 39-61 (1 pi.). 
