32 



the soap larvicide used in Panama are given and various other larvicide 

 preparations are mentioned. The introduction of fish into water 

 reservoirs is also recommended. 



Brethes (J.). La Mosca Brava. [Stomoxys calcitrans.] — Anales Soc. 

 Rural Argentina, Buenos Aires, lii, no. 8, August 1918, pp. 496- 

 498, 2 figs. [Received 27th November 1918.] 



A short account is given of the life-history and habits of Stomoxys 

 calcitrans, and the importance of cleanHness in stables and places 

 where the fly breeds is emphasised. If a breeding-place of the fly 

 should be discovered, control measures should be based on the fact 

 that the larvae descend into the ground about two inches, rarely more, 

 to pupate. Holes should therefore be drilled with a stake, about 

 6 to 8 inches deep at intervals of about a yard. Into each sufficient 

 carbon bisulphide should be poured to fill a couple of walnuts [s?'c] and 

 the holes at once filled in. This will penetrate the soil and kill any 

 larvae or pupae within the area treated. 



Bacot (A). Mosquitoes and the Danger of Malaria in England. — 



Essex Naturalist, xviii, pp. 241-263, 4 plates, 3 figs. [Received 

 12th November 1918.] 



A brief general account is given of mosquitos, their life-history and 

 habits, particularly those species that are responsible for the dissemi- 

 nation of diseases, a description of these being given and the choice 

 of breeding-places of the various species compared. The history of 

 malaria in England is briefly reviewed, the disease probably having been 

 introduced after the Norman conquest. During the latter half of the 

 19th century it gradually died down, owing probably in part to improve- 

 ments in drainage and in part to the use of quinine. The cause for 

 such disappearance in some localities is, however, difficult to determine ; 

 in South Essex, for instance, malaria is said to have practically 

 disappeared since the 18th century, although the marshes have been 

 drained for 300 years in the same manner as now. Two charts show 

 respectively the distribution of Anopheline mosquitos and the past 

 occurrence of malaria in England. A comparison of these shows that 

 the distribution of the disease is more restricted than that of the 

 mosquitos. At the outbreak of the AVar. apart from a few imported 

 cases, malaria was probably extinct. The factors necessary for the 

 continuance of the cycle of the malaria organism are discussed, and 

 it is pointed out that malaria can only exist during the period in which 

 the temperature is high enough to allow the parasite responsible for 

 the disease to develoj) within the body of the mosquito. Within this 

 limit the survival of malaria will depend upon the period during 

 which the organism can linger on in the system of its human host, 

 coupled with the prevalence of mosquitos when any recrudescence, 

 due to hardship and exposure, occurs. These two factors are amenable 

 to human influence, and as England is situated at the limit of the 

 range of the disease it should not be difficult to control it in this 

 country. The prevention of the infection of mosquitos when a malarial 

 subject has a renewed attack of fever is difficult, but not impossible. 

 If there were a thoroughly organised national medical service the 



