388 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
kidney shows a great resemblance to the end-cells of the excretory 
system of Turbellaria, and, in the author’s opinion, the resemblance is 
such as to confirm the view that Mollusca arose from a Turbellarian-like 
ancestor. 
Egg-capsules of Gastropoda."' — Mr. J. T. Cunningham in a short 
note describes the process of egg-laying in Buccinum undo turn, and states 
that the egg-capsules are formed by the sole-gland of the foot, which is 
thus to be regarded as a nidamental gland. He has noticed the same 
thing in Murex erinaceus, and believes that the egg-capsules of Azygo- 
branchs will be found to arise always in this way. 
5. Lamellibranchiata. 
Cephalic Eyes of Lamellibranchs. f — Prof. Paul Pelseneer briefly 
summarises his observations on this subject. He finds that in certain 
genera of Mytilidae, and of the related genus Avicula (exclusive of 
Meleagrina'), a pair of cephalic eyes occur, which are simple pigmented 
pits with a cuticular lens. They occur both in the larva and in the 
adult, but may not appear in the larva until the formation of the anterior 
branchial filaments. In the larva they are placed beneath the posterior 
border of the velum ; in the adult, on the first filament of the gill-plate. 
They are probably homologous with the larval eyes of Chiton , and not 
with the cephalic eyes of Gastropods. 
Arthropoda. 
ct. Insecta. 
Pigment Formation in Wings of Butterflies.^ — Herr Franz Fried- 
mann has investigated the development of pigment in the pupa of 
Vanessa urticse. His results differ, in several respects, from those of 
A. G. Mayer.§ He finds that the pigment arises from a fatty substance, 
produced by the blood-cells, but the latter do not themselves enter the 
scales. The formation of pigment can be seen only in preparations fixed 
with osmic acid, on account of the solubility of the antecedent of the 
pigment in alcohol. The general plan of the coloration is clearly indi- 
cated as early as the fourth day after pupation. 
The Orthopteran Genus Schistocerca.|| — Mr. S. H. Scudder pub- 
lishes a monograph on this American genus, in which he describes forty- 
four species. 
Seasonal Dimorphism in Lepidoptera.^f — Mr. Roland Trimen, in his 
presidential address to the Entomological Society, reviews generally the 
w r ork which has been done on this subject during the last two decades, 
both on European and tropical forms. He refrains from drawing any 
general conclusions, but urges the necessity for renewed and more care- 
ful observation, especially in the case of tropical forms. 
* Nature, fix. (1899) p. 557. t Arch. Biol., xvi. (1899) pp. 97-103 (1 pi.). 
X Arch. f. Mikr. Anat., lv. (1899) pp. 88-95 (1 pi.). 
§ Cf. this Journal, 1896, p. 514. 
|| Proc. Amer. Acad., xxxiv. (1899) pp. 441-76. 
4 Nature, fix. (1899) pp. 568-73. 
