30 



MOSQUITO WoKK IN KIIAKTOUM, ETC. 



Regulations for 

 the prevention 

 of malaria 

 generally 



A ' ' mosquito 

 plant" 



No. Strength of Solution, 

 r>h 1 iu 50,000 



(iil 



1 ill ;io,uoo 



(ib 1 in oO,UOO 



8 



1 iu 10,000? 

 some suspended 



matter. 

 1 iu 1,000? 

 much deposit. 



Result. Temp, of Water. 



Liirxie of Pyi-etophorufi costalis all alive 28-5'^C 



after 48 liours. A few alive after 72 



liours and after 90 liours. Pupa^ formed. 



Discontinued. 

 Culex fatiyans. Nearly all the lar\ii? Do. 



dead •\vithin 40 hours. Some alive 



after 72 hours. All dead -within 



4 days. 

 Larvie and pupa; of Ciilcr futiyniis and Do. 



Pyrctojihorufi costalis. \ ery sluggish 



in 20 lioui-s. Some dead. Some ali\'e 



at the eud of 24 hours. AU dead 



except oue larva and one pupa of 



Culex fatigans within 44 hours. All 



dead in about 50 hours. 

 Killed larva; of Culex fatujans within Do. 



18 hours, nut in 5 liours. 



Do. 



Killed advanced larvas of Culex fatigann 

 in 25 minutes. 



All the larvas and pupa; kiUed were stained a bright yellow. The solutions 

 soon altei-ed a little in strength OAving to evaporation, and, as will be seen, the 

 results were somewhat indefinite. 



Mosquito work has not, however, been confined to Khartoum. At the 

 request of the S.M.O. Khartoum one drew up a set of simj)le regulations, ■\\ath 

 reference to the prevention of malaria, for the use of outlpng stations. It Avas 

 on the hnes of Major Ross's recommendations, and in addition, care was taken 

 to include those measures rendered necessary by the disco\ery, made by those ' 

 who \\ix\Q worked ^vitli forest mosquitoes, of breeding places in pitcher plants 

 and holloAv trees holding Avater. 



From Kassala, Captain Ensor reports a great improvement both as regards 

 mosquitoes and other noxious and annoying insects Avliich pass their lar\-al stages 

 in water. In this connection, it is interesting to note that the ShiUuks have a 

 so-called " mosquito plant." They dry the leaves and lay them inside the roofs 

 of their huts. The myth of the basil,- if not that of the neem, has been 

 exploded, so that probably this precautionary measure is of no value. I have 

 not been able to obtain a specimen of the plant. 



Mr. Cross brought the laboratories specimens of ^lansonia uniformis from 

 Renk, and Dr. Cliristopherson sent certain mosquitoes he collected up the Blue 

 Nile. Unfortunately, these had not been mounted and were much damaged. The fact 



' Lntz. Cent. f. Bakt., &c. Bd. xzziii., No. 4, Jan. 1903. Leicester. Journal of Tropical Medicine, 15/9/03 

 ' Prout's Experiments. Tlu Times, London, 27 7/03 



