102 H. M. WOODCOCK. 



Section III. Historical. 



The first observation of a Trypanosome is probably to be ascribed to Valentin 

 (117), who, in 1811, announced his discovery of Ama3ba-like parasites 

 in the blood of a trout. In the two or three years immediately following, 

 Remak, Berg, and othei's recorded the occurrence of Ha^matozoa which 

 were undoubtedly Trypanosomes in various fishes. The observers usually 

 remarked upon the transparent, membranous portion of the body, with a 

 denticulate fringe or border, — the well-known appearance presented by the 

 undulating membrane when in motion. The parasite of frogs appears to have 

 been first seen by Gluge (1842), and in July, 1843, Mayer (73a) described 

 and figured certain corkscrew-like and amoeboid organisms from the blood 

 of the same animal, which he termed variously Amoeba rotatoria, and 

 Paramcecium costatum or lovicatura. A few months later (November) 

 Gruby (25) also published an account of this organism, to which he gave 

 the new generic name of Trypanosoma. The same parasite was subse- 

 quently described and figured by Lankester (30) in 1871, who, unaware of 

 Gruby's work, called it Undulina ranarum ; this author was the first to 

 indicate the presence of a nucleus (fig. 1 b) in the organism. The next 

 discovery was that by Lewis, in 1878, of the form parasitic in Indian rats. 

 This Trypanosome was named Herpetomonas lewisi' by Kent, and has 

 since been shown to be of common occurrence in sewer- rats throughout the 

 world. Trypanosomes were first met with in cases of disease by Griffith 

 Evans, who in 1880 found them in the blood of horses suffering from 

 Surra. The organisms were thought by him to be Spirilla. Steel (110) 

 rediscovered the same form five years later in transport mules in British 

 Burmah which were suffering from an " obscure and fatal disease." He 

 took a similar view with regard to its affinities, and named it Spirochaeta 

 e van si. An early description, with figures, of this parasite was given by 

 Crookshank (1886). 



To Mitrophanow (1883 to 1884) and Danilewsky (1885 to 1889) we owe the 

 first serious attempts to study the comparative anatomy of these Ha^matozoa. 

 The work of the latter in particular does not appear to have received as 

 much attention as it deserved. This author examined many birds and fishes, 

 and endeavoured to fit the various phases of the parasites met with in each 

 case into their proper place in the life-cycle. Considering the difficulties of 

 technique with which Danilewsky had to contend, his researches merit 

 great commendation. Some of his figures of a Trypanosome of birds are 

 reproduced in fig. 3. Unfortunately the complete absence from his writings 

 of any system of nomenclature, which leads to the same form being often 



• This form is now placed in the genus Trypanosoma for reasons which 

 will be given in the Systematic section. 



