360 APPENDIX. 



speck is very striking ; and in other cases again the 

 posterior filament is only faintly tinged, or an unstained 

 spot occurs near its base. 



The morphological identity of the rat and Surra 

 parasites is thus established, and both seem morpho- 

 logically identical with the organism of Mitrophanow. 

 If we follow Mitrophanow we must, therefore, enlarge 

 his genus of Hcztnatomonas. The author ventures, how- 

 ever, to disagree with Mitrophanow in the advisability of 

 adopting this entirely new generic name. Mitrophanow 

 suggested this new term because of the special habitat 

 normal fish- blood of the species he discovered. But 



FIG. 135. MONADS IN RAT'S BLOOD, showing membrane under different 

 aspects, blood-corpuscles some crenated, and stained discs, X I2co. 



the characteristic features of these organisms are the 

 characteristic marks of the genus Trichomonas^ They 

 are, therefore, embraced by the genus Trichomonas, and 

 there is no need to create a new one. If it were not 

 for the different description given by Mitrophanow of the 

 organism in the blood of Cobitis fossilis, the author would 

 be inclined to say that all these organisms belonged to 

 one and the same species, which might well be named 

 Trichomonas sanguinis. The monads in the rat and the 

 Surra parasite have been shown to be morphologically 

 identical with each other, and both, as far as one can 

 * Vide Leuckart, The Parasites of Man, translated by Hoyle, 1886. 



