SÉANCE DU 3 FÉVRIER loi 



cytes. In one guiiiea pig, a mule and the raccoon, there were collec- 

 tions of lymphoid cells surrounding the portai spaces, extending from 

 one space to another, and out into the lobule. Thèse mononuclear cells 

 appeared to hâve phagocyted and replaced hepatic cells and showed 

 évidences of active multiplication. There was such an unwonted stimu- 

 lation of the lymphocytes, apparently resulting from a spécifie trypano- 

 toxin (Laveran and Pettil), that they were not only being made in the 

 usual sites, but in various viscera, as well as by prolifération in the 

 blood stream. Megakaryocytes, nucleated red cells and eosinophiles 

 were not detected in the hepatic nécroses, although a few free megaka- 

 ryocytes were seen in the sinusoidsof the liver of Nijctipithecus. Thèse 

 portai collections of cells are inconstant and they are interpreted as 

 peripheral zone nécroses such as are seen in certain intoxications. 



Their constituent cells were idenlical with cells seen on the périphéries 

 of malpighian bodies of the spleen and they appeared to hâve come from 

 that source. They are the seat of karyokinesis, as Pettit has shown in 

 other trypanosomal infections, and they appear to act as " fîeld outfits" 

 in contradistinction to " base supplies " for the production of lympho- 

 cytes to be used in the mechanism of défense. 



Kidney : Nephritis of several types was not^d; in small rodents, 

 parenchymatous degeneration was the rule, while in mules, acute 

 glomeruhtis and foci of hemorrhages and polymorphonuclear leucocytic 

 exudation were noted in addition, [n the monkeys, dog, raccoon and 

 coati there were linear interstitial collections of cells, chiefly mono- 

 nuclear, like those in the hepatic portai nécroses, and resembling those 

 described by Councilman in scarlatina. In the raccoon thèse collections 

 of cells contained eosinophiles, as well. Megakaryocytes and nucleated 

 red cells were not présent. 



Areas of dermatitis and orchitis in the guinea pig contained peri- 

 vascular and other collections of mononuclear cells exactly like those 

 in the liver and kidney. 



[Board of Health Laboratory. Ancon, Canale Zone.) 



RÉSUMÉ. — L'action de Trypanosoma hippicum, sur les diverses 

 espèces de Mammifères expérimentées par Darling, se traduit par les 

 phénomènes suivants : 



1° Dégénérescences cellulaires ; 



2° Anémie et lymphocytos.e ; 



3° Ecchymoses; 



A° OEdème; 



5° Hyperplasie des tissus lymphoïde et myéloïde; 



6° Infiltrations de tissus lymphoïde et myéloïde au niveau de la rate, 

 du foie, du rein, de la peau et du testicule. 



