74 



cassia and peppermint, light wood oil, and crude naphthaline and cam- 

 phor. Observations on the behaviour of the mosquitos during the 

 tests suggest that the protection afiorded does not result from a 

 dislike of the insects to the culicifuge, but to its obscuring the attrac- 

 tiveness of the human odour. 



It being a matter of general belief that some individuals are more 

 prone to mosquito attacks than others, the point was tested experi- 

 mentally and showed that the factor of preference on the part of the 

 mosquito does exist. 



Hall (M. C). A Note regarding Myiasis, especially that due to Syrphid 

 Larvae. — Arch. Internal Med., Chicago, III., xxi. no. 3, 15th 

 March 1918, pp. 309-312. 



A number of published cases are enumerated in which myiasis has 

 apparently been due to Syrphid larvae, which are stated to have been 

 present seventeen times in the digestive tract of man, once in the 

 nostrils of man and twice in the vagina of cattle. 



Moore (W.). Impregnation of the Underwear as a means of Controlling 

 the Clothes Louse. — Jl. Amer. Med. Assoc, Chicago, III, Ixxi, no. 

 7, 17th August 1918, pp. 530-531. 



The experiments briefly described in this paper showed creosote 

 and heliotropine to be the two most favourable compounds tested 

 for impregnating underwear against Pediculus humanus. A 10 per 

 cent, solution of creosote in lubricating oil. used at the rate of 1 c.c. 

 to 8 square inches of material, worn next to the skin, was elTective 

 for 24 hours, after which it lost its toxicity. With heliotropine, 

 used at the rate of 1 grm. with cocoa butter 3 grms. (dissolved in 

 ether, carbon bisulphide or benzine) per 48 square inches of material, 

 the underwear could be worn for 168 hours without loss of toxicity. 



To have lasting qualities chemicals must not be less volatile than 

 a compound boiling between 300° and 350° C, while the most toxic 

 compounds are those with boiling points of 265° C. or lower ; helio- 

 tropine has a boiling point of 263° C. It is said to kill 100 per cent, 

 of the lice within 12 hours, but no mention is made of its efEect on 

 the eggs, 



Geiger (J. C), PuRDY (W. C.) & Bates (L, I,). Malaria Endemicity 

 of the Rice Districts of Louisiana and Arkansas, with some 

 Observations on Types of Mosquitoes breeding therein. — Jl. Amer. 

 Med. Assoc, Chicago, III., Ixxi, no. 16, 19th October 1918, pp. 

 1283-1285, 1 map. 



Anti-malarial work near an aviation field among rice-fields is 

 described. As it is not yet possible absolutely to control mosquitos 

 in rice-fields, recourse was had to dealing with the human carrier 

 and to efficient screening. These measures rendered the malaria 

 incidence negligible, and were very necessary owing to the persistent 

 breeding of Anopheles quadrimacvlatus. This mosquito was first 

 found in the latter part of June and by 10th July had superseded 

 A. crucians and A. 'punctipennis, which were the only species found 



