22 



and that therefore no new infections of the mosquito took place after 

 that date. It was not until February that half-grown oocysts were 

 again found. 



It is often said that mosquitos cannot become infected during 

 hibernation, because they no longer suck blood. This is incorrect 

 as regards Anophelines, at least in Holland, where they feed throughout 

 the winter in houses and, even more so, in stables and cowsheds. 



These findings disagree with the very general view that no infected 

 Anophelines can be found in winter, or that if there be infected 

 individuals their oocysts will degenerate without maturing. 



The fact that in man malaria occurs mostly in summer and not in 

 winter, when a greater percentage of infected Anophelines occurs 

 indoors, is easily understood if it is remembered that in summer there 

 are many more Anophelines and that they suck blood more frequently. 

 With regard to the point that in winter almost no new human infections 

 are observed. Dr. Swellengrebel's investigation shows that oocysts 

 can mature in winter, and the supposition that the sporozoites lose 

 their virulence during prolonged residence in the salivary glands loses 

 its force in view of the fact that Anophelines feed in winter. It is 

 therefore thought that man can be infected with virulent sporozoites 

 in winter without this becoming apparent. This leads to the assump- 

 tion that a portion of the primary spring human cases are dae to this 

 cause. Whether all such sj)ring cases may be thus explained depends 

 on further spring investigations. 



Lepneva (S. G.). Anopheles macuUpennis, Meigen. B OKpecTHOCTflX 

 Capaioea. [In the Environs of Saratov.] — TpyAbI CapaiOBCKOrO 



OSmecTBa EcTecTBOMcnbiTaTeneii ii JlioOMTejieii EciecTBOSHaHMfl. 



[Trans. Saratov Soc. Naturalists], viii, no. 1, PaQOTbl BOHWCKOM 

 BuOJlorHHeCKOil CiaHl^HH IWork of the Volga Biol. Sta.], Saratov, 

 V, no. 4-5, 1921, pp. 250-253. [Received 23rd November 1921.] 



Anopheles macuUpennis, Meig., has been found breeding in practic- 

 ally all collections of water examined in the environs of Saratov. In 

 a part of the town known to be highly infected with malaria no Anophe- 

 line larvae were found. This may be accounted for by the polluted 

 state of the river and the absence of vegetation in it ; the main 

 breeding area is apparently a neighbouring lake, and from this the 

 adult Anophelines invade the town. 



A brief summary in German is appended to this paper. 



Profilaxis de la Peste. Estudios para el Saneamiento de Bolsas de 

 Arpillera. [Plague Prophylaxis. Studies on the Cleansing of 

 Bags made of Sacking.] — Anales Dept. Nac. Higiene, Buenos 

 Aires, xxvii, no. 3, May-June 1921, pp. 105-115. [Received 

 23rd November 1921.] 

 The majority report of a committee studying the question of freeing 

 grain bags from plague germs and rat -fleas recommends further experi- 

 ments with a chamber in which hot air is kept in motion [cf.R. A.E., B, 

 ix, 197, 198]. A minority report, signed by Dr. R. Kraus, recommends 

 further investigation on the question of hot circulating air and hot 

 still air, for if the latter gives as good results — as researches made 

 hitherto appear to indicate — this will enable a very simple type of 

 air chamber to be used. 



