53 



possible to speak of a seasonal prevalence of plague — the duration of 

 the period of infectibility of the rat-flea, Xenopsylla (Loemopsylla) 

 cheojpis, was observed to be longer than in British India. The observa- 

 tions are shown in a table, from which it appears that the infestation 

 of Mus rattus griseiventer (common house rat), M. concolor (small 

 house rat) and M. rattus diardii (field rat) differ but httle, a result in 

 accordance with their infection under natural conditions. The period 

 of infectibility of the flea extended to 43 days, the longest period yet 

 reached in transmission experiments without artificial conditions of 

 temperature and moisture. The period of 43 days occurred on 

 M. concolor, those for M. rattus griseiventer being 36, and for M. diardii, 

 37 days respectively. 



VAN Breemen (M. L.). Een voorloopig Onderzoek' betreffende de 

 verschillende Soorten van Anophelinen, te Soerabaia voorkomende. 



[A preliminary Investigation on the various Species of Anophelines 

 occurring in Soerabaya.] — Geneesk. Tijdschr. v. Nederl.-Indie,^ 

 Batavia, Ivii, no. 3, 1917, pp. 325-329. 



During 1916 the author collected at Soerabaya (Java) the larvae of 

 Anopheles barbirostris, A. sinensis, A. rossi and A. rossi var. indefinitus ; 

 in the early part of the same year larvae of A. kochi were also taken. 

 It is remarkable that malaria should be common, while none of the 

 generally recognised carriers are to be found. A, ludlowi, which 

 Stanton found at Semarang, is absent from Soerabaya, where A. rossi 

 appears to be the predominant species and comprised nearly all the 

 specimens taken indoors. Investigations in August, when the disease 

 was at its height, demonstrated sporocysts in the fifteenth specimen 

 of A. rossi examined, though whether this mosquito was infected 

 with the human malaria parasite was impossible of proof. Further 

 investigation is necessary to ascertain whether A. rossi is actually the 

 principal malaria carrier at Soerabaya and whether it has replaced 

 A. ludlowi in this role in the eastern portion of Java. 



SwELLENGREBEL (N. H.). Myzomyia rossi, Giles, M. ludlowi, Theo., 

 en M. indefinita, Ludl. — Geneesk. Tijdschr. v. Nederl.-Indie, 

 Batavia, Ivii, no. 4, 1917, pp. 490-495, 1 plate. 



These three mosquitos are closely allied morphologically, and at 

 least one of them is becoming suspect of transmitting malaria. The 

 present paper records the differences between them with a view to 

 preventing any confusion. 



DE Raadt (0. L, E.). De Rol van de Huisrat in de Epidemiologie der 



Pest. [The Role of the House-rat in the Epidemiology of Plague.] 

 — Geneesk. Tijdschr. v. Nederl.-Indie, Batavia, Ivii, no. 4, 1917, 

 pp. 520-533, 1 fig. 



The author disagrees with Otten's statements that rats play only a 

 minor part in the spread of plague in Java and that the house-rat is 

 seldom met with in the fields there [see this Review, Ser. B, v, p. 65]. 

 As regards the latter point, he instances cases in support of his own 



