410 CHARLES H. T. TOWNSEND. 



well illustrated by fig. 1 , PL VII, of the report, from a mild case of verruga. Attention 

 is especially called to McGuire's blood smears, for they demonstrate the Bartonella 

 gametes in the erythrocytes, positively caused by the experimental bites of the Phlebotomus 

 in a subject who had never entered a verruga zone. 



It is said that verruga- eruption infection may be transmitted in a similar manner 

 to that of smallpox (p. 160). This is positively contra-indicated, not only by the 

 hundreds of verruga cases in all stages of the eruption treated in open ward without 

 a single new case arising therefrom, but also by the writer's recently published 

 interpretation of the asexual cycle of the Bartonella,'^ and the latter's evident 

 dependence upon the Phlebotomus for transmission. 



Matucana, Peru, altitude 7,800 feet (wTongly given 7,300 in the report), situated 

 in the dilute upper limits of the Rimac verruga zone, appears to be the only point 

 in the infected region where any one of the authors has spent a night (p. 160). 

 Entomological investigations in •the dilute limits of the zones are obviously not 

 greatly productive of results bearing on the transmission of the disease. Invitation 

 extended by the writer to the authors at the time to spend one or more nights with 

 him in Verrugas Canyon, the centre of the infected zone, was declined. Some insects 

 were collected by the authors at Surco and San Bartolome during daylight, but no 

 night work was done. Thus they secured no insects that have any bearing on the 

 transmission of verruga. Not a single specimen of the Phlebotonms was secured 

 by them, though it was present at Matucana during their visit.f 



It is stated that the relationships of Bartonella indicate that it should be 

 transmitted by a tick (pp. 171-2). It can be said positively that this is a futile idea. 

 The writer and his assistants dragged Verrugas Canyon at various seasons with 

 flannel cloths, through herbage and over bare rock and soil, in all kinds of situations, 

 and not a single tick was secured in this manner. The only ticks obtained in the 

 verruga zone were Boophilus annulatus, on horses and cattle ; Ixodes lagotis, on 

 vizcacha ; Ixodes sp.,on rats; and Argas sp., on Athene and goatsuckers. All of 

 these species occur outside the verruga zone as well as within it. The relationships 

 of Bartonella (whatever they may be, and whether rightly or wrongly interpreted by 

 the authors) to the contrary notwithstanding, no tick can possibly be the vector 

 of verruga. As a matter of fact, Bartonella does not appear to be at all closely related 

 to the distinctively tick-borne protozoa. However, relationship of host counts for 

 little in parasitism ; the real requisite is correspondence of conditions furnished by 

 the host. 



The supposition is ventured that the mosquito, Phalangomyia debilis, Dyar & Knab, 

 found at Matucana, may occur throughout the verruga zone (p. 172). There is no 

 possibility of such being the case. The writer made collections of all the adult 

 mosquitos that he could find in the verruga zone, both indoors and out-of-doors, by 

 day and night, and did not meet with this species at all. The form is a very peculiar 

 one and evidently confined to the higher region above the centres of verruga infection. 

 Matucana is more than 2,000 feet above Verrugas Canyon. 



* Jl. Wasliington Acad. Sci., v, no. 21 (1915). 



t Peru To-day, vi, pp. 57-8 (1914) ; Anales de Zool. Apljcada, Santiago, Chile, i, p. 45 

 (1914). 



