140 



])atc]ies at the lower levels. Surface drains proved unsatisfactory, 

 owing to their constantly becoming clogged, and a deeper system of 

 draining was necessary, leading to a common outfall where the water 

 was oiled with an automatic drip. Irrigation wells were oiled ; other 

 wells were fitted with pumps or lids. In other respects the work 

 against breeding places was carried out on the usual lines, automatic 

 drips resulting in a considerable saving of labour, while over half the 

 oil used was waste oil. 



The Anophehnes found were A. maculipennis and A. bifurcatus, the 

 former being more often infected. Their numbers showed a marked 

 fall during the summer, instead of the usual rise, omng to the success 

 of the work done. It was found that mosquitos could fly as far as a 

 mile and a quarter to the camp. The anti-mosquito work was supple- 

 mented as far as possible by attempts to protect the troops from 

 mosquito bites by quinine issues and the isolation of carriers. The 

 results were very successful. Only a fractional percentage of primary 

 infection occurred, probably only one case among several thousand 

 troops. By contrast the neighbouring Italian anti-aircraft battery 

 had a primary infection rate of 45'3 per cent., 26"4 per cent, becoming 

 permanently ineffective. 



Hearle (E.). Notes on some Mosquitoes new to Canada. — Canad. 

 Entom., London, Ont., lii, no 5, May 1920, pp. 114-116. 



Mosquitos recorded as new to Canada, and of which brief descriptions 

 are given, include Janthinosoma {Psorophora) scuji, D. & K., of which 

 a single specimen was taken in Ontario in August, attempting to bite 

 at 8.30 a.m. Aedes triseriatus, Say, which has formerly been recorded 

 in the United States east of the Rocky Mountains, is fairly common in 

 the woods of southern Ontario. Females only were taken and were 

 found to bite fiercely during the day. Larvae were taken from a tree- 

 hole in July. A. aldrichi, D. & K., was found to be the dominant 

 mosquito in Fraser Valley, B.C. in 1919, having been previously re- 

 corded only from Montana and Idaho. The development of this 

 species in Fraser Valley is apparently dependent on the fluctuations 

 of the river. In seasons when the cotton-wood valleys around the 

 river become flooded it is extremely abundant. The adults bite viciously 

 and are so small that they can easily penetrate ordinary screening. 

 Anopheles quadrimaculatus , Say, is apparently common in some 

 parts of southern Ontario, though there are no previous records of its 

 occurrence in Canada. 



Stefanopoulo (G. J.). Sur la Presence du Spirochaeta icterohemor- 

 ragiae chez les Rats d'Egout, a Paris. — C.R. Sac. Biol, Paris, 

 Ixxxiii, no. 18, 29th May 1920, pp. 811-812. 



In March 1920, Spirochaeta icterohaemorrhagiae was discovered in rats 

 {Mus decumanus) taken from the sewers of Paris, and was inoculated 

 into guinea-pigs which duly developed the disease (infectious jaundice). 

 Previous examinations of sewer rats in Paris have given negative 

 results. It is noteworthy that the spirochaetes were found after an 

 unusually mild winter when human cases had been particularly 

 numerous, and the infected rats were taken from the locahty where 

 it is known that epidemics occurred in 1865. 



