190 r. Current Literature. 91 



Malarial Mosquitoes in Ireland. 



Everyone who lias scanned with any care recent scientific or even 

 general literature, knows that researches during the last few years by 

 Ross, Grassi, and others have established the fact that the protozoan 

 parasites whose presence within human red blood-corpuscles causes 

 the various forms of ague and malaria, are passed into the system by the 

 bite of the female gnats or mosquitoes of the genus A/iofiheles. The 

 asexual development of the parasite is carried on in the human body, 

 the sexual generation within the body of the insect. It is highly 

 probable that malarial infection is only conveyed by the bite of Anopheles, 

 and could this genus of gnats be exterminated, malarial disease would be 

 completely stamped out. In the first number of the newly-issued Journal 

 of Hygiene are two papers illustrated with maps and plates on this 

 very interesting subject. Drs. Nuttall and Cobbett and Mr. Strange- 

 ways-Pigg write on the distribution of Anopheles in the British Isles in 

 relation to the former distribution of ague^while Dr. Nuttall and Mr. A. 

 E. Shipley describe in much detail the structure and habits of the larva 

 of A. maculipennis. The species of Anopheles are shown to occur in all 

 those parts of the country which were formerly malarious, but they also 

 inhabit other parts where there is no record of the former prevalence of 

 the disease. It seems therefore that Grassi's suggestion that the 

 distribution of Anopheles and of malarial disease would be found to 

 correspond throughout the world cannot be sustained. Still there is a 

 very general agreement between the English counties where ague was 

 formerly prevalent and those which Anopheles still inhabits. Dr. Nuttall 

 and his companions believe that the disappearance of ague from these 

 countries is due to a reduction in the number of Anopheles together 

 with a reduction in the human population of those low-lying, marshy 

 districts which were the centres of malarial infection in former times. 

 The distribution of Anopheles has been tabulated with great care, and 

 except for Haliday's Co. Down record of the three British species, in 

 1833, the only Irish entry is a recent capture at Harold's Cross of a female 

 A. nigripes, which is now in the Dublin Museum, 



Underground Crustacea. 



In the Linnean Society's Journal {Zoology) vol. xxviii., 1900, pp. T40- 

 162, pis. 16-18, Dr. C. Chilton gives an interesting account of the 

 subterranean Amphipoda of the British Isles. There are four species — 

 three of Niphargus and one of Craugonyx, found in deep wells and other 

 underground waters. It is remarkable that all seem restricted to the 

 southern counties of England except Niphargus kockianus, Speuce Bate, 

 specimens of which, recently collected by Mr. Farrau in wells near 

 Dublin, were examined by Dr. Chilton. This species occurs also in 

 Hampshire and Wiltshire in southern England, and at Munich, Bavaria. 



