68 



poisons used against the adult flies nearly always contained sugar or 

 syrup as a bait. The best poisons were black arsenic and castor oil. 

 The latter may be rendered almost instantaneously fatal to flies by 

 the addition of a little croton oil [2 drops per 30 grms. of castor oil]. 

 Ground-nut oil was useless as a poison. A small amount of black 

 arsenic added to a plateful of water quickly kills the flies attracted 

 to it. Arsenious acid is very much less efi&cacious. 



SiKORA (H.). Beitrage zur Kenntnis der Rickettsien. [Contribution 

 to the Knowledge of Rickettsia spp.] — Archiv. f. Schiffs- u. Tropen- 

 Hyg., Leipzic, xxii, no. 24, December 1918, pp. 442-446. 



Ricksettsia melophagi, which occurs in the stomach lumen and on the 

 surface of the stomach epithelium of the sheep louse, Melophagus 

 [ovinus], is abundant in mature individuals but rare in young ones. 

 According to experiments described in this paper the infection is 

 hereditary in Melophagus. Clothes-lice did not contract infection 

 when allowed to feed on sheep. From cat fleas bodies were obtained 

 that are similar to R. wolhynica and are provisionally named 

 R. ctenocephali. Rickettsia-\ike forms were also obtained from mouse 

 fleas, but both the rat flea and human flea appear to be uninfected. 



KuczYNSKi ( — ). Bacterium proteus Xig (Weil-Felix) in der Kleider- 

 laus. [Bflctermm ^rotews Z19, Weil-Felix, in the Body-Louse.] 

 — Archiv. f. Protistenkunde, Jena, xxxviii, no. 3, 27th April 1918, 

 pp. 376-391, 4 figs. 



The question of the aetiology of typhus fever has not yet been 

 solved. Part of the difference of opinion centres round Bo,cillus typhi- 

 exanthematici, Rickettsia prowazeki and Bacterium proteus X/g, each of 

 which has been claimed to be the causal agent. The author draws 

 attention to the contradiction involved in the assumption that sterile 

 lice acquire Rickettsia from healthy human individuals, for this 

 presumes an accumulation of such Rickettsia in the blood-stream of 

 the human host. The importance of Rickettsia proivazeki is not 

 invalidated by the Rickettsia findings in Volhynian fever. In order to 

 solve the question of the relative importance in the pathogenesis of the 

 disease of the various organisms found in typhus-infected blood the 

 method of artificial infection of lice with pure cultures is suggested 

 and has been carried out in the case of Bacterium proteus X/g. It 

 was ascertained that X/p and Rickettsia are not identical and that Xig 

 shows a characteristic growth in size in lice that led to the death of 

 the experimental lice within 72 hours or less. It is probable that a 

 contemporaneous infection of lice with Rickettsia impedes the develop- 

 ment of X/g. It is very probable that the rod- and thread-forms in 

 lice infected with Rickettsia do not belong to that organism but to Xig. 

 As a result of a personal experiment in which 72 lice artificially infected 

 with X/g were allowed to feed during a period of 3 weeks on the author 

 it appears to be highly improbable that X/g is pathogenic to a healthy 

 man. Some clinical observations however suggest that a primary 

 illness or great general debility may render X/g pathogenic to a 

 certain degree. 



