124 



Tephrosia vogeli on mosquito larvae ; all those placed in a 1 per cent, 

 solution of pulp made from the leaves died in 12 hours. Before this 

 is tried on a large scale, the effect on domestic animals must be tested. 



Flies are not abundant considering the conditions prevailing, though 

 Musca domestica becomes troublesome at times in the residential 

 part of the town, while Chrysomyia {Pycnosoma) spp. and Sarcophaga 

 spp. are prevalent in the markets. 



Larvae of Chrysomyia {Pycnosoma) bezzianum, Vill., have been 

 obtained in great numbers in sores from donkey's ears, generally 

 associated with suppuration. 



Bakber (M. a.). Some Observations and Experiments on Malayan 

 Anopheles with special Reference to the Transmission of Malaria — 



Philip)pine Jl. Sci, Manila, xiii, Sec. B., no. 1, January 1918, 

 pp. 1-47. [Received 22nd April 1918.] 



This paper describes experiments on the capacity of Malayan 

 Anophelines to transmit malaria, various species being dealt with. 

 At the time when the experiments were begun, only one form of 

 A. rossi, Giles, had been reported from the Malay Peninsula, namely, 

 A. rossi var. indefinitus, Ludl. Among the material collected it became 

 obvious that there were two types present, though it is doubtful 

 whether the typical form of Malaya may not be distinct from A. rossi, 

 Giles, of India. The habitat of the two Malayan forms is described ; 

 A. rossi var. indefinitus most frequently occurs in muddy pools 

 exposed to the sun, while the typical form is never found in such 

 habitats, but frequents clear pools surrounded with grass or other 

 vegetation. In experiments to determine the susceptibiUty of these 

 two forms to malaria, the typical form was shown to be a much more 

 important potential carrier. 



A series of tables records the results of the experiments. It is 

 obvious that the probability of infecting a mosquito depends on 

 factors other than the number of gametes present in the carrier at 

 the time of feeding. The explanation of the great variability in the 

 infectivity of gamete-carriers independently of the percentage of 

 gametes in the blood is not apparent. It is suggested that this is 

 due to a disparity in numbers of the sexes of the gametes. It may be 

 also that in the presence of a sufficient number of both sexes there is 

 in the gametes some biological factor, not apparent morphologically, 

 which determines their fertihty. Possibly gametes originating in the 

 same oocysts, or in the same mid-gut, are less mutually fertile than 

 those from more widely differing sources. Further data are necessary 

 to elucidate this point. 



The author summarises the conclusions regarding the infectivity of 

 the various species as follows : — 



Anopheles ludlowi. Much evidence has been adduced by Christo- 

 phers and others indicating that A. ludlowi is an important carrier 

 of malaria in certain coast regions. The high percentage of infections 

 with ready formation of sporozoites observed in the experimental 

 series described in this paper, as well as the finding of a naturally 

 infected specimen with sporozoites in the salivary glands, would go 

 to confirm the evidence already obtained regarding the dangerous 

 character of this species. 



