205 



diaidii), and in a few localities, Mus norvegicus, were captured. The 

 fleas found were mostly Xenopsi/Ua cheojyk ; Pijgiopsijlla ahalae Avas 

 not common. The number of fleas showed periodic variation and there 

 were more rat-fleas in the plague-infected areas than in those apparently 

 plague free. The variations in number bore a definite relation to 

 climatic conditions and frequently, though not always, rose and fell 

 with the number of plague cases. The view of the English Plague 

 Commission that annual plague epidemics are connected with the 

 periodic variation in the number of fleas is borne out by the Java 

 figures, but the author regards the rise in number during an epidemic 

 not as the cause, but rather as the effect, and due to accompanying 

 concentration. The number of rat-fleas in Java varied greatly in 

 dift'erent localities and bore no relation to the spread of the plague, 

 which may possibly account for the fact that the intensity of the 

 epidemic varied so greatly in different districts. The author is convinced 

 that the normal flea population is an important factor, though not the 

 only one, in the intensity of an epidemic. 



Maggio (C.) & RosENBACH (F.). Studien iiber die Chagaskrankheit in 

 Argentinien und die Trypanosomen der "Vinchucas" Wanzen 



[Trialoma itifestans, Klug). [Studies of C'hagas' diseases in Argen- 

 tina and of the Trypanosomes of Trialoma infestans.] — Cenlmlhl. 

 f. Bakt. Parasitenkunde etc., Jena, 8th September 1915, I. abt. 

 originale, Bd. 77, Heft I, pp. 40-46, 2 plates. 

 Chagas infected healthy individuals of Triatoma infestans with 

 trypanosomes of the blood of men and animals and determined that 

 from 8 to 10 days was required before the insect became infective. 

 The special conditions required for infection are not yet fully known ; 

 bugs which have bitten infected humans or monkeys are capable of 

 transmitting the disease, but this is not the case if they are fed on 

 infected guineapigs. Brumpt was of opinion that the organism could 

 be transferred also by the faeces of bed-bugs deposited upon 

 the skin or mucous membranes. In Salta, the authors have been 

 able to prove that Triatoma infestans contains in its intestinal 

 tract numerous flagellates which closely resemble those described by 

 Ohagas ; these are described in detail. Bugs from the northern 

 provinces of the Argentine exhibit flagellates in more or less large 

 numbers, while those from the southern regions, such as Rio Negro 

 and Bahia Blanca, were free from parasites. Possibly the lower 

 temperature of these areas is not favourable to the development of 

 the trypanosome. Of 171 insects from Salta, 71 were infected ; the 

 adults showed a much higher proportion of infection than the larvae 

 and nymphs, 59 against r8 per cent. This leads to the suspicion that 

 the adults had become infected outside the houses, where almost the 

 whole of the material examined was collected ; the existence of an 

 outside animal carrier or reservoir is possible. Laboratory observations 

 show that the whole life-cycle of T. infestans is completed in 1 \ years 

 in Buenos Aires ; there was no sign of flagellates in the second 

 generation and hereditary transmission seems to be excluded. When 

 healthy and infected bugs were kept together and allowed to feed on 

 healthy animals, the healthy insects were found to become infected 

 after 3 months. The infection probably takes place through ingestion 



