ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
73 
of sausage-skin-like envelope around tke food in the mid-gut of the 
larva is cuticular in its origin. 
Alimentary Canal of Anthrenus Larva.* * * § — Dr. A. Mobusz lias an 
interesting paper on this subject, which deserves a longer summary than 
we can give it. He describes the general and the minute structure, 
with some interesting physiological notes by the way. Thus he 
advances strong reasons for regarding the Malpighian tubes as more 
than excretory; they absorb fluid food from the caecum, pass it to 
various parts of the body, and receive waste material in exchange. 
There is complete epithelial regeneration of the mid-gut during the 
larval moultings. The gut is emptied, the intima of the stomodaeum 
is separated off and passes into the mid-gut, the muscularis contracts 
energetically several times, the basal membrane of the mid-gut is 
hoisted off, the crypts beneath spread out and form a new epithelium. 
The metamorphosis in the pupa is to be regarded as an intense moult- 
ing, or the moulting as a weakened metamorphosis, the differences being 
quantitative, not qualitative. 
Development of Platygaster.f — Prof. N. Kulagin has made an 
extended series of observations on the development of this important 
parasite of Cecidomyia. He finds that it occurs in the larvae of a large 
number of Diptera, Hemiptera, and Hymenoptera. The larva inhabits 
the fatty body of the host, and pupates at the same time as the host. 
If the host has been infected by more than one egg, it does not survive 
pupation, but if by only one, the attack is apparently not fatal. The 
author gives an account of the formation of the germ-layers, of the 
development of the external form, and of the derivatives of the ectoderm, 
mesoderm, and endoderm in Platygaster , adding in each case compara- 
tive notes to show the relation of his own observations to those of others 
on the development of the parasitic Hymenoptera. The result is to 
show that Platygaster is most nearly related to the genus Teleas, studied 
by Metschnikoff and Ayers. This is shown by the absence of yolk in 
the egg, and the consequent formation of a typical blastula, and by the 
simple organisation of the larva, which is parasitic throughout life. In 
one species of Platygaster it was found that the sex-cells were distinct 
at the time of the formation of the mesoblastic somites, that is, before 
mesoderm and endoderm were differentiated from one another. 
' j Chromatin Reduction in Spermatogenesis of Pentatoma.J — Dr. T. 
H. Montgomery, jun., finds 14 chromosomes in the spermatogenetic 
mitoses ; they appear in the reduced number (7) in the first spermato- 
cyte ; in the succeeding divisions they undergo two transverse divisions 
(reducing divisions) ; and at no stage is there any evidence of a longi- 
tudinal division (equation division). The author compares his results 
with those reached in regard to the allied Pyrrhocoris by Henking. 
Symbiosis between a Butterfly and a Flower .§ — Herr E. Ule 
describes a singular relationship between a butterfly, Danais Euripus, 
and the flower of an asclepiad, Asclepias curassavica, in Brazil. The 
* Arch. Naturges., lxiii. (1897) pp. 89-128 (3 pis.), 
t Zeitschr. wiss. Zool., lxiii. (1897) pp. 195-235 (2 pis.). 
t Zool. Anzeig., xx. (1897) pp. 457-60 (9 figs.). 
§ Ber. Deutsch. Bot. Gesell., xv. (1897) pp. 385-7. 
