32 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
in the venation, and will proceed to consider specialisation by addition. 
In dealing with the wings of Coleoptera in the present instalment, they 
conclude that elytra are modified wings, and find the strongest evidence 
in the very close correspondence which exists between the tracheation 
of the elytra and that of the hind-wings. 
Regeneration in Phasmidse.* * * § — M. Edmond Bordage has shown that 
the regeneration of legs after artificial mutilation occurs only in the 
region of the tarsus and the lower third of the tibia ; and he seeks to 
explain this limit as an adaptation related to the most probable breakages 
when the insects are attacked by lizards (Calotes versicolor ), and when 
the larva is escaping from the egg-shell. Similarly, he ingeniously 
seeks to explain the fusion of the trochanter and femur in relation to 
the strains put upon this region in the process of eedysis. The line of 
fusion, which he compares to ankylosis, forms a place of least resistance 
along which autotomy may most readily occur. What was a functional 
modification to start with has become a constitutional character, favoured 
by what the author somewhat quaintly terms “ exuvial selection.” 
Surely it is none the less natural selection because its point d’appui is 
in the process of exuviation. 
Development of Chrysomelidse.t — A. Lecaillon has studied Clytra 
Iseviuscula, Gastrophysa raphani , Chrysomela mentastri , Lina populi, L. 
tremulse, and Agelastica alni. We cannot do more than state a few of 
his results. There seems to be no chitin in the envelopes of the ovum. 
The segmentation is typical, but intravitelline is a much better term for 
it than superficial or peripheral, since the nuclei are at first scattered 
in the vitellus. Most move to the periphery and form the ectoderm ; 
those that remain internally form the endoderm. At this early stage the 
sex-cells are recognisable, apparently arising from the ectoderm. The 
mesoderm has an ectodermic and a very variable origin. Epithelial 
strands growing from the stomodaaum and the proctodmum complete the 
gut, which is therefore wholly ectodermic. Indeed, in higher insects 
generally there is no endoderm in the adult, and in some cases (parasitic 
Hymenoptera) there is no rudiment of it even in the embryo. Thus 
the author is in close agreement with Heymons. 
Mosquitoes and Malaria.J — Prof. Grassi has published another 
preliminary note in support of his theory that various “mosquitoes” 
(Anopheles claviger, Culex penicillaris, and Culex malarise ) are agents in 
spreading malaria. He refers to the work of other writers who have 
suggested a connection between malaria and mosquitoes. 
5. Arachnida. 
Oocytes of Pholcus. § — Prof. Ch. Van Bambeke gives a detailed 
account of his researches on the ovum of Pholcus phalangioides Fuessl. 
The first chapter discusses the origin and growth of the safraninophilous 
* CR. Soc. Biol., July 1898, 6 pp. 
t ‘Recherches sur l’ceuf et sur le developpement embryonnaire de quelques 
Chrysomelides. Theses presentees a la Faculte des Sciences de Paris,’ Ser. A, 
No. 299 (1898) pp. 1-219 (4 pis. and 2 figs.). See Zool. Centralbl., v. (1898) 
pp. 813-6. X Atti R. Acad. Lincei (Rend.), vii. (1898) pp. 234-40. 
§ Arch. Biol., xv. (1898) pp. 511-98 (6 pis.). 
