ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 439 



proximally an expansion of nerve-fibres inclosed in a special wall, and 

 distally a darker " nucleus " in the middle of which lies a rod-like some- 

 what refractive body. The nerve-fibrils come into close association with 

 this peculiar body, and distally a thin process passes to the hypodermis. 

 Besides the eyes, the antennas, the sensory hairs described by Weismann, 

 the brown spot which Leydig regarded as a third rudimentary eye, and 

 the organ described, there is also a minute chordotonal organ, so that 

 the head is extremely well equipped. 



Synonymy of Musca Marginalis.* — E. E. Austen clears up the 

 synonymy of this much-described species. Its systematic position is 

 now fixed in the genus Pycnosoma, in which there are two species, 

 P. marginale and P. chloropyga. These, together with Musca domestica, 

 it appears, were partly responsible for the spread of enteric fever among 

 the British soldiers during the late war in South Africa. 



Distribution and Biology of Anopheles.f — J. R. Adie and 

 A. Alcock record the occurrence of Anopheles (Myzomyia) listoni in 

 Calcutta in December and January. Some experiments were made in 

 order to discover natural enemies of the larvae. In one cage where 

 there were twelve larvas and a single rapacious larva of a dragon-fly 

 (Ceriagrion coromandelianus) all the Anopheles larvae disappeared, and 

 an adult dragon-fly hatched out in due course. 



Development of Ageniaspis Fuscicollis.J — F. Silvestri has studied 

 the development of this parasitic Hymenopteron, whose poly-embryony 

 has been investigated by Marchal. It is an " endophagous " parasite of 

 Prays olcellus. 



In the maturation of the parthenogenetic ova, as in the fertilised, 

 two polar bodies are formed. The whole of the protoplasm of the ovum 

 does not take part in forming embryonic cells, for a polar portion, in- 

 cluding the polar globules, assumes a protective and nutritive function 

 as regards the embryonic portion. 



Collecting Stylopida3.§ — Charles Dury gives a useful hint. In the 

 genera Xenos and Stylops, the adult female is larvif orm and never leaves 

 the body of its host (wasp, bee, etc.), but the male pupa projects. A 

 wasp so infected should be confined in a jelly tumbler with a cheese- 

 cloth cover over the top ; in the bottom of the glass there should be 

 placed a round bit of blotting paper and a piece of screen wire, raised up 

 from the bottom. When the Xenos emerges it falls through the false 

 bottom of wire. Otherwise the wasp would bite it in pieces. The wasp 

 should be fed with jelly and water, put on the cheese-cloth cover in one 

 small spot with a camel's hair brush. 



Copulation and Oviposition in Hemiptera.|| — C. Gordon Hewitt 

 has observed these phenomena in several aquatic genera. In Nepa 

 cinerea, where there is a terminal respiratory siphon, the chief interest in 



* Ann. Mag. Nat. Hist., xcix. (1906) pp. 301-4). 



t Proc. Roy. Soc, Series B, lxxvi. (1905) pp. 319-21. 



j Atti Rend. R. Accad. Lincei Roma (1906) pp. 650-7. 



§ Ohio Nat., vi. (1906) p. 443. 



|| Trans. Entomol. Soc. London, 1906, pp. 87-90 (1 fig.). 



