430 RESEARCH IN PROTOZOOLOGY 



agglutinated trypanosomes in dilutions higher than i :ioo, but 

 that serum from animals immunized with dead trypanosomes 

 showed titres as high as i :i6oo and from infected animals might 

 reach i : 12,800. Group reactions (though to a less extent) were 

 obtained with T. cquiperdmn, T. brucei and T. gambiense. The 

 test antigens consisted of washed trypanosomes suspended in 

 saline and preserved in formalin. This work was corroborated 

 and amplified to include other trypanosomes by Winkler and 

 Wyschelessky (1911) who indicated that the test might be of 

 diagnostic value in dourine and compared favorably with parallel 

 complement fixation and precipitin tests; by Mattes (1912); by 

 Ruppert (1912); by Lanfranchi (1912) who obtained signally 

 high titres by a technique not described; by Ofifermann (191 5) 

 who concluded from a study of rabbits during the course of 

 infection with T. cquiperdum that complement fixation was some- 

 what superior to agglutination ; and by Marcone and de Gaspari 

 (1921). 



A long series of investigations are in accord in demonstrating 

 that the serum of many animals develops a trypanolytic property 

 which is associated with periodic disappearances of the organisms 

 from the blood. Rodet and Vallet (1906) conducted a valuable 

 study of the lysins arising during the course of uninfluenced 

 infections of the pathogenic trypanosomes. This work was con- 

 tinued and amplified by MassagHa (1907), Levaditi and Muter- 

 milch (1909), Leger and Ringenbach (1911 and 1912) and Muter- 

 milch and Salamon (1928). 



D. Malaria. Malaria has attracted a great deal of attention 

 because various observers have reported that dififerent stages of 

 the disease, especially of sestivo-autumnal, yield positive Wasser- 

 mann tests and a few have gone so far as to suggest its use in 

 the diagnosis of malaria. Nevertheless, at present, the general 

 trend of opinion seems to be that malaria, without concomitant 

 yaws or syphilis, only yields positive Wassermann tests with 

 faulty technique. Among several recent excellent reviews of the 

 subject attention may be called to that of Lloyd and Mitra (1926) 

 who pointed out that: (i) the so-called Wassermann test has 

 been carried out in a variety of ways; (2) the highest proportion 

 of positive tests in malaria has been obtained by workers using 

 Wassermann's original method; (3) in many positive tests syphilis 

 has been inadequately excluded; and (4) workers using mod- 



