ZOOLOGY AND BOTANY, JIIGROSCOPY, ETC. 377 



g^rubs, with a hard chitinous head sunk in the first segment of the body- 

 The mandibles are powerful. The body is curved in relation to t^Q 

 larva's method of progressing by alternately extending and distending, 

 pressing on the sides of its tunnel. In the Anobiid types this is helped 

 by spinules. The legs are very feeble. The antennee are much reduced 

 and sunk in pits, except in the Lyctid type. No eyes w^ere seen. The 

 various larvae are dealt with in accurate detail. 



Life-history of Tachinarians.* — W. R. Thompson discusses the 

 intra-muscular stage in the development of Pla{/ia trepida Meig. and 

 Sturiiiia scutellata Rond. The eggs of Plagla, containing larvae ready 

 to hatch out, are laid on the body of the host. The larva traverses the 

 skin, and entering the general cavity passes thence into a muscle, 

 where it remains till the end of the primary stage. Tt then forms a 

 secondary tegumentary air-hole, in connexion with which it passes the 

 second and third stages. It leaves the host before pupation. 



The eggs of Sturmia are laid on the leaves which the host eats. 

 Devoured by a caterpillar, the eggs hatch in the alimentary canal, and 

 the larvas pass out into the general cavity and thence into a muscle. It 

 applies its stigmata against a bunch of its host's tracheae near a stigma 

 and forms a sort of tracheal sheath, within which it remains until the 

 end of the third stage. 



The muscles react differently in the two cases. In the case of 

 Sturmia, a simple cutaneous muscle becomes a large lobed sac with 

 thick walls. Striations and fibrils disappear ; the size of the nuclei 

 increases, and their numbei" as well (apparently by direct divisions) ; the 

 chromatin breaks up into a mass of fine granulations. 



In the case of Flagia there are no striking changes for some time. 

 Thus the striations persist. The final change takes place somewhat 

 suddenly, death and disintegration taking place rapidly. The substance 

 of the muscle is used up by the parasite. In Sturmia there is hyper- 

 trophy of a living fibre ; in Flagia there is breaking up of a dead fibre. 

 Phagocytes are few or absent around the fibre in Sturmia ; they are 

 numerous, naturally enough, in Plagia, where they are doubtless 

 attracted by chemotaxis. 



When it enters a muscle the larva of Plagia is much larger than that 

 of Sturmia ; its initial mechanical effect is more violent. At the end of 

 the first stage the proportions are reversed. The growth of Sturmia in 

 the first stage is much greater than that of Plagia, and the duration 

 of the stage is much greater. The salivary secretion of the larva is 

 more abundant in Sturmia than in Plagia, and the salivary glands are 

 larger, especially towards the end of the first stage. 



Life-history of a Nycteribiid.f — J. Rodhain and J. Bequaert 

 discuss the life-history of Cydopodia grceffi Karsch, parasitic on a Congo 

 bat {Cyiionycteris straminea). The insects often remain for hours 

 motionless on their host ; they suck blood at frequent intervals ; they 



* C.R. Soc. Biol. Paris, Ixxviii. (1915) pp. 717-21 (5 figs.), 

 t Bull. Soc. Zool. France, xl. (1916) pp. 2i8-62 (i figs.). 



Aug. 16th, 1916 2 D 



