490 PROTOZOA 



roth/' has a preventive and curative effect in mice infected with mal de 

 coder as. The curative effect is especially marked. As late as three days 

 after infection with the trypanosome cures are effected. Inasmuch as 

 the " trypanroth" is non-poisonous for the trypanosome in vitro, Ehrlich 

 and Shiga suppose that a toxic substance is formed in the mice. The 

 preventive effect of the trypanroth soon passes off, allowing the mice to 

 become infected with trypanosomes two to three days after a preventive 

 inoculation. On other trypanosomes and in other animals the results 

 are not so good. Alternating arsenic and " trypanroth " may give 

 better results. 



Serum Therapy. Various normal sera from different animals have been 

 tried, with practically no success. A few have prolonged life. Thus 

 Laveran and Mesnil state that human serum injected in sufficient 

 quantities shows manifest action on the disease, and that sometimes 

 cure results in mice and rats. Further, by alternating human serum 

 with arsenic they obtained better results still. Kanthack, Durham, and 

 Blandford showed that animals recovering from trypanosoma infection 

 were immune to further infection. Rabinowitsch and Kempner have 

 made a very careful study of immune serum produced by the trypano- 

 soma Lewisi. Not only have they shown that an animal may be hyper- 

 immunized and that then its serum in comparatively large doses inocu- 

 lated into mice at the same time as the trypanosomes, or twenty-four 

 hours before or after, allows no development of the organisms; but 

 also Laveran and Mesnil state that the serum causes their rapid 

 destruction by the leukocytes, though MacNeal, on the other hand, 

 states that they are destroyed by a cytolytic action of the serum. This 

 immune serum also has a similar action on the trypanosoma of Dourine. 

 The serum of animals hyperimmunized against other varieties of try- 

 panosoma is not as active as that obtained by the inoculation of 

 trypanosoma Lewisi, mal de caderas giving the best results so far, but 

 results that are not encouraging for practical treatment. 



Koch suggested that an immunity might be established by the inocu- 

 lation of attenuated parasites, and Novy and MacNeal have succeeded 

 in attenuating cultures of trypanosoma Brucei, and have obtained some 

 success in protecting experimental animals against virulent cutures. 



Spirochsete Obermeieri (Spirillum of Relapsing Fever). 



Until very recently this organism was classed with the bacteria, but 

 it is now placed by Schaudinn and others with the flagellates, as it has 

 many of the characteristics of the trypanosomes. 



This spirochaete was first observed by Obermeier in 1873 in the 

 blood of persons suffering from relapsing fever. It was found in large 

 numbers during the height of the fever, it disappeared about the time 

 of the crisis, and reappeared during the relapses. It was not found in 

 other diseases. Obermeier considered it the cause, of the disease, and 

 his views were shown to be correct by the production of the disease in 

 man and ape through experimental inoculation. 



