în lhe peripheric circulation and tlieir 

 existence in the tissues of these patients. 

 My observations were made in human 

 dwelling-places abundantly infested by 

 triatomata. In one of these I found a cat 

 evidently ill and in whose blood \ipon exa- 

 mination, was loimd Trypanosoma Cruzi. 

 Tliis did not, however, allow of a defi- 

 nite conclusion, since the cat, being a 

 domestic animal, passes tlie night in 

 human dwelling places and is conse- 

 quently exposed to being sucked by the 

 insects, so that its infection could be no 

 siH'prise. And besides, from later exami- 

 nations I came to the conclusion that 

 the cat is a reservoir for trypanosomes, 

 and for this very reason a factor in the 

 spreading of the disease. 



Pursuiníí my work, and I must ad- 

 mit I did it with a well-foimded certa- 

 inty of success, 1 had the chance of fin- 

 ding in a feverish condition a child from 

 lhe house in which I had found tlie infec- 

 ted cat. Now, a fortnight or twenty 

 (lays before, I had spent a night in the 

 house and had seen a great number of 

 insects stinging the dwellers including 

 the little girl who now lay feverish and 

 who at the time had been in perfect 

 health. 



Among the chief clinical symptoms 

 of this child, whose fever had come 

 on some eight or ten days before exa- 

 mination, where the following: Axillary 

 temp. 40oC; spleen enlarged and to be 

 felt imder the edge of ribs; liver also 

 enlarged; groups of peripheric lymphatic 

 glands swollen etc. Most noticeable was 

 a generalised infiltration, more prono- 

 raiced in the face, and which did not 

 show the characters of renal œdema but 

 rather of myxœdema. This last symp- 

 tom, which I later found to be one of 

 the most characteristic of the acute form 

 of the disease, already then revealed so- 

 me functional alteration of the thyreoid 

 gland, perhaps affected by the patho- 

 genic action of the parasite. 



Examination between covcr-giass 



end slide revealed the existence of fla- 

 gellates, in good number and The fixing 

 and staining of blood-films made it pas' 

 sible to characterise the parasite's mor- 

 phologi] and to identify it with Trypano- 

 soma Cruzi, first seen in crithidia-form 

 in the intestine of Triatoma and trans- 

 mitted by the sting and by inoculation 

 of the flagellates taken out of the intes- 

 tine, first to the monkey Callithrix (Cal- 

 lithrix penicillata) and then to several 

 small laboratory animals. 



Thus was proved the existence of a 

 new trypanosomiasis of man. This was 

 the second one known; its parasite sho- 

 v.ed well defined morphologic and 

 ])iologic cliaracters distinguishing it 

 from any other known trypanosome. The 

 transmitter of the new disease as shown 

 '/y undeniable laboratory experiment* 

 was a heteropteron of the genus irlatoma, 

 Triatoma megista. 



There remained now to be carried 

 thiougli careful studies as to the patho- 

 genesis, symptomalogy epidemiology and 

 geographic distribution of the new di- 

 sease which 1 had discovered in it» 

 acute form. Was it always like this or 

 did it show well-defined chronic fonms t 

 My clinical experience and knowledge of 

 the imusual diseased condition of local 

 inhabitants led me to admit that in 

 tiiis trypanosomiasis, besides the known 

 acute form, other chronic ones awaited 

 detection and description. 



I was only able to take up again 

 these researches some months later, 

 with the clinic and epidemiologic pro- 

 blems of the disease, up to then almost 

 entirely obscure, now as my object. la 

 this also my knowledge of the local no- 

 sology, in which I had come upon con- 

 ditions impossible to understand, was of 

 great use to me. Returning to the study 

 of the disease with a better grasp of tlie 

 problem, I tried to systematise the facts 

 so as to get a starting-point for possible 

 generalisations. Among the symptoms 

 what most impressed me was the fre- 



