66 



Herms (W. B.) & Freeborn (S. B.). The Egg-laying Habits o! 

 Californian Anophelines. — Jl. Parasit., Urbana, III, Vn, no. 2. 

 December 1920, pp. 69-79, 2 figs. 



Observations made during May, June and July 1920 on the egg- 

 laying habits of Anopheles quadrimaciilatiis occidenialis, Say, A. 

 punctipennis, Say, and A. pseudopundipennis, Theo., are described 

 in detail. The factors governing the time of egg deposition are not 

 known, but light, temperature, humidity and wind probably have 

 an important influence. 



The actual process of deposition was observed only in the case of 

 A. punctipennis. The incubation period of this species ranges from 

 two to six days, with an average of 3-2 days, that of A . qnadrimaculatiis 

 from two to four days, with an average of 2-5 days. It seems highly 

 probable that temperature exercises a decided effect on incubation, 

 particularly at the extremes, but within a range of 68° to 76° F. 

 little effect was noticed. In connection with desiccation experiments 

 it was found that the eggs of A. quadriviaculaUis could withstand 

 drying for 72 hours, but those of A. punctipennis failed to hatch 

 after drying for 24 hours. 



Herms (W. B.). Malaria Control.— il/Z/z/j-. Bull. California State Bd. 

 Health, Sacramento, xvi, no. 5, November 1920, pp. 15-ld,. 

 [Received 4th February 1921.] 



The danger of malaria and resulting economic losses, as well as the 

 possibihty of remedial measures, are briefly discussed. The University 

 of Cahfornia, in co-operation with the State Board of Health, have 

 undertaken investigations into the life-histories and habits of, as well 

 as remedial measures against, the mosquitos occurring within the limits 

 of the State [R.A.E.. B, viii, 92-93]. Observations here recorded 

 in connection with the eggs of the Californian Anophelines are noticed 

 in the preceding paper. 



PuRDY (W. C). Should Rice-raising be prohibited near Towns?— 



Mthly. Bull. California State Bd. Health, Sacramento, xvi, 

 no. 5, November 1920, pp. 78-81. [Received 4th February 

 1921.] 



The advisability of prohibiting the cultivation of rice in the vicinity 

 of towns owing to the risk of malaria is discussed [cf. R.A.E., B, 

 V, 142]. The danger from the presence of this crop depends on the 

 relative abundance of malaria-carrying mosquitos. In justice to all 

 concerned it is suggested that careful investigations into the breeding- 

 places of mosquitos and the prevalence of malaria in the district 

 concerned should precede any curtailment of rice-growing. 



Hornby (H. E.) . The relative Pathogenicity for Cattle of Trypanosoma 

 congolense and T. vivax. — Vet. JL, London, Ixxvii, no. 2, 

 February 1921, pp. 77-78. 



As a result of examination of the blood and gland juice of cattle in 

 South Africa, it is concluded, in connection with inoculation experi- 

 ments, that native cattle may recover spontaneously from T. vivax 

 infection, but that no great immunity results therefrom. Infections 

 with T. congolense generally prove fatal. 



