21 



moor, we have been troubled every summer with the enchDsed gnats, 

 which, coming into the bedrooms, assail the sleepers to such an extent 

 that we have to adopt mosquito curtains." 



Anopheles maculipenuis, which occurs throughout Europe and has 

 been met with in Palestine, is also widely distributed in Canada and 

 the United States. 



Before bringing to a close these brief notes on the British represen- 

 tatives of the malaria-bearing genus Anoplieles, it may be interesting 

 to reproduce the following " Conclusions " from the paper by Messrs. 

 Nuttall, Cobbett, and Strangeways-Pigg already referred to {loc. 

 at. pp. 43-44). 



" I. The disappearance of ague from Great Britain does not 

 depend upon the extinction of mosquitoes capable of 

 harbouring the parasites of malaria. 



" 2. Three species of Anopheles {A. iiiacnlifenins,A. bifiircatus, 

 A. nigripes) are to be found in Great Britain in all districts 

 which were formerly malarious, but also in places con- 

 cerning which there is no record of the former prevalence 

 of ague. 







The Anopheles to-day are most numerous in low-l\-ing land 

 containing many ditches, ponds, and slowly-flowing water, 

 suitable for their habitat, and corresponding to the dis- 

 tricts where ague was formerly prevalent. 



" 4. Since the disappearance of ague does not depend upon 

 the extinction of Anopheles it is probably due to several 

 causes operating together : 



" {a) A reduction in the number of these insects conse- 

 quent upon drainage of the land, this being in accord 

 with all the older authors, who attributed the disappearance 

 of ague largely to this cause. 



" {b) Reduction of the population in infected districts 

 as the result of emigration about the time when ague dis- 



