54 



view, and concludes that in the fields Otten sought the house-rat in 

 localities where the conditions were abnormal. The house-rats, Mus 

 raftiis griseiventer and M. concolor, were found by the author to an 

 extent varying from 5 to 9 "6 per cent. Otten also obtained a similar 

 proportion (8.5 per cent.) in one instance where his own figures show a 

 low Xenopsylla cheopis index (0"12) in the field-rats, i.e., where the 

 mortality of the house-rat was small ; in cases where Otten was unable 

 to find the house-rat this was due to high mortality corresponding to a 

 high index (0"80) in the field-rat. The great importance of the house- 

 rat, especially M. rattus griseiventer, in spreading rat-plague is therefore 

 again brought into the foreground. 



It is remarked that Otten's paper might lead the reader to infer 

 that the primary reservoirs of the out-door flea, Pygiopsylla ahalae, 

 are in the fields. These are in fact in the woods, where favourable 

 developmental conditions are constant, which is not the case in the 

 fields. 



Otten (L.). Over de Biologic van Mus concolor. [The Biology of 

 M. concolor.] — Geneesk. Tijdsclir. v. Nederl-Indie, Batavia, Ivii, 

 no. 4, 1917, pp. 534-568. 



The author disagrees with most of the conclusions reached by 

 De Raadt in the latter's investigations concerning the biology of the 

 Javanese house and field-rats [see this Review, Ser. B, iv^ p. 128]. His 

 own results include some already published [see this Review, Ser. B, 

 V, p. 65] and he also states that the rat population of woods and coffee 

 estates is either non-existent or very scanty. Together with Mus 

 jerdoni and the field-rat [M. rattus diardii] a few specimens of the house- 

 rat, M. concolor, are present, while the other house-rat, M. rattus 

 griseiventer, is not. The field-rat and M. concolor living out-doors are 

 exclusively parasitised by Pygiopsylla ahalae, a true out-door flea, 

 which however occurs as a facultative house-flea in hilly districts. 



NoLLER (W.). Blut- und Insektenflagellatenziichten auf Flatten. 

 [The Plate Culture of Flagellates from Blood and from Insects.] 

 — Archiv. /. Schiffs- u. Trop.- Hygiene, Leipzic, xxi, no. 4-5, 

 February-March 1917, pp. 53-94, 3 figs., 1 plate. 



This is a technical paper the subject-matter of which is indicated 

 by the title. 



Werner (H.) & Wiese (0.). Die Uebertragung von Rekurrensspi- 

 rochaten dureh Kopflause. [The Transmission of Recurrent Fever 

 by Head Lice.] — Arch, f. ScJii^s- u. Trop.- Hygiene, Leipzic, xxi, 

 no. 8, April 1917, p. 139. 



Cases of recurrent fever among civilian workers on the Eastern Front 

 provided an opportunity of ascertaining the increase of Spirochaeta 

 recurrentis in the head-louse, Pediculus capitis. Eleven examples 

 taken from a healthy person were placed upon a recurrent fever 

 patient at the height of the fever. Eight days later, two of these 

 individuals were found to be heavily infected with spirochaetes. 



