TITLES. 
Ins. 19 
172. Exnf.r, S. Ueber Cylinder welche optischo Bilder entwerfeu. 
Arch. ges. Phys. xxxviii, pp. 274-290. 
A contribution to the physics of optical scieuce discussing the forma- 
tion of images by lenses of peculiar' form, each facet of the insect eye 
being treated as actually a cylindrical lens. The memoir is largely 
mathematical. 
173. Fabre, J. H. Souvenirs entomologiques (troisieme s6rie). Etudes 
sur Pinstinct et les moeurs des Insectes, 433 pp. Paris : 188G. 
This is not only an account of a series of most remarkable and ingeni- 
ous observations on the habits of Insects, but is also a very weighty 
polemic from the point of view of an observer of" instinct against the 
theory of transformism, or common descent. It contains some highly 
remarkable histories of metamorphoses in various orders, Hymenoptera 
being, however, the Insects most largely dealt with. There are twenty 
chapters: — The first four are devoted to the habits of Scolia , more 
especially S. bifascia ta , and the manner in which its larva lives at the 
oxpense of the larva of Cetonia ; and ho argues that the remarkable com- 
bination of perfect instinctive actions he portrays for us, could never 
have arisen by natural selection from ancestors with other instincts. 
This, indeed, is the leading idea of the book, to display the wonderful 
and minute perfection of the instinctive actions necessary for the main- 
tenance of the existence of the species, and to show that the existence 
being only maintained by this perfection, we are bound down to a theory 
of uniformity, v. Les parasites, is chiefly devoted to the theory of 
mimicry, which he considers to be an illusion that should be allowed to 
pass into oblivion, vi. La theorie du parasitisme, discusses the variety 
of instincts and habits included under the term parasitic, and shows that 
parasites work quite as hard as the insects they prey on, and have an 
organization specially adapted to their lives, thus rejects the theory 
that parasitism arose from occasional indulgence in habits of preying, 
and that these gradually became confirmed, vii. Les tribulations de la 
Ma^onne, relates to the habits of Chalicodoma muraria and pyrenaica r 
and the insects that live at their oxpense, or take possession of their con- 
structions. The next three chapters are devoted to details of the modes 
in which three of these insects — Anthrax trifasciata y Leucospis gigas , and 
Monodontomerus cupreus — destroy the larva of the Chalicodoma. xi. Le 
dimorphisme larvaire, gives an account of the discovery of two totally 
different forms of larva in Anthrax trifasciata , Leucospis gigas , Sapyga 
punctata , and probably also in Myodites subdipterus ; the first form he 
calls the form of acquisition ; it does not take nourishment, but has, for 
sole object, to obtain possession of the food, and this done, undergoes a 
complete change of external structure, xii. Concerns the habits of species 
of Tachyta , more especially of Tachyta ) n. sp. ?, and the manner .in 
which it paralyses Mantis religiosa. xiii describes the metamorphoses of 
Cerocoma schaffleri, Mylabris Yl-punctata , and Zonites preeusta. xiv. 
Changement de regime, concerns the difficulty in effecting a change of 
habits among the predaceous Hymenoptera, the subject being continued 
in the next chapter, “ une piqftre au transformisme,’’ in which he argues 
