ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 
193 
chirping together they keep time as if led by the wand of a conductor. 
The rate of chirp, he says, seems to be entirely determined by tempera- 
ture ; so much so that the temperature may be easily computed if the 
number of chirps is known. Thus at 60° F. the rate is 80 per minute, 
at 70° F. it is 120; this gives a change of four chirps for each degree. 
Below 50° F. the cricket has no energy to waste, and the rate is only 40 
chirps per minute. 
Chromatic Tetrads in Spermatogenesis of Grasshopper.* — Dr. E. 
Y. Wilcox answers Dr. E. B. Wilson’s criticism of his account of the 
spermatogenesis in Calopterus , and adheres to his previous conclusions. 
The doubling of the normal number of chromosomes in the prophases 
of the first maturation division is not due to a longitudinal splitting of 
the chromosomes. In the spireme of spermatocytes of the first order 
the chromosomes arise separately and independently, but afterwards 
become associated in pairs, and then by conjugation form tetrads, the 
components of which are all unlike. 
Development of Heart in Agelastica Alni.f — Herr A. Petrunke- 
witsch describes the origin of the heart from a closure of the mesoderm 
on the dorsal median line of the embryo. Thus there is formed a canal, 
which Tichomiroff called gastro-vascular, with walls consisting exter- 
nally of mesoderm, and internally (but only in part, i.e. ventrally) of 
cndoderm. But it is perhaps enough to say that the author confirms 
what Tichomiroff described in Bombyx mori and Sphinx ocellata. 
Apterygota of Kiew.| — A. Scherbakow gives a list of the Collembola 
and Thysanura of the Kiew district, enumerating 67 species and 19 
varieties. He describes a new genus Mesira , and three new species. 
Lepidoptera injurious to Sugar-Cane.§ — M. Edmond Bordage dis- 
cusses Diatroea striatalis and Sesamia noncigriodes whose larvae, known as 
“ Borers,” do injury to the sugar-cane in Reunion and Mauritius. The 
identity and synonymy of these two forms seems to have got strangely 
jumbled, and the note is intended to put matters straight. 
Psyche Helix. || — Herr I. Ingenitzsky has some notes on the life- 
history and habits of Psyche ( Epichnopteryx ) helix Sieb., whose larvae, 
pupae, and female imagines live in earth-like coiled tubes like snail- 
shells. It occurs very abundantly in Central Asia, sometimes damages 
even cultivated plants, and appears to be sometimes parthenogenetic. 
Its state in the different seasons is described. 
Myriopoda. 
Segmentation of Myriopod Body.T — Dr. R. Heymons points out the 
close resemblance between the development of Chilopoda and Hexapoda. 
On the head-region of the Scolopendra-hlsiStodeTm the following seg- 
ments are seen: — (1) Antennary, (2) intercalary, (3) mandibular, 
(4 and 5) two maxillary segments. Then follows, as in all Chilopods, a 
* Anat. Anzeig., xiv. (1897) pp. 194-8. 
I Zool. Anzeig., xxi. (1898) pp. 140-3 (3 figs.). % Tom. cit., pp. 57-65 (9 figs.). 
§ Comptes Eendus, cxxv. (1897) pp. 1109-12. 
II Zool. Anzeig., xx. (1897) pp. 473-7 (1 fig.). 
SB. K. Preuss. Akad. Wiss., 1897, pp. 915-23 (2 figs.). 
