A. Porter 
385 
distinct from Herpetomonas, the undulating membrane and the an¬ 
teriorly tapering body of the adult Grithidia being quite unlike the 
appearance of the Herpetomonas, while the nucleus and blepbaroplast 
of the Grithidia are nearer together than those of Herpetomonas 
(Text-fig. 1, a, h). The flagellum also is somewhat different in the two, 
for in Grithidia, it is more of the nature of the chromatic border of 
the undulating membrane of a Trypanosome (Text-fig. 1, c), while in 
Herpetomonas, the flagellum is free and no membrane is present. There 
is also a distinct difference in the movements of the two organisms, 
sufficient to differentiate between the parasites in general observation. 
These points surely should be sufficient to deter anyone from placing 
such different organisms in one and the same genus. Personally, I 
believe that the genus Herpetomonas 1 should be retained, as it was 
originally constituted, for flagellates each possessing one flagellum and 
Text-fig. 1. Diagrams of (a) Herpetomonas, (b) Crithidia, (c) Trypanosoma —to show 
the chief morphological differences between these genera, especially as regards the 
flagellum and undulating membrane. 
1 An interesting discovery has been made by Lafont (vi. 1909) of a flagellate, Herpeto¬ 
monas (Leptomonas) davidi, parasitic in the latex of Euphorbia pilulifera, a shrub common 
throughout the tropics. The parasitised plants, suffering from a condition which the 
author terms “ flagellosis,” lose their leaves, and their growth suffers. 
Vincent has found the flagellate in Euphorbia thymifolia as well as in E. pilulifera in 
Reunion. The plants were infested with small Hemiptera, and it is suggested that these 
are the carriers of infection. Donovan (xi. 1909) has also found the flagellate in 
E. pilulifera of Madras. 
I have had the opportunity of examining a preparation, sent from Madras, of 
the flagellate from Euphorbia, and consider it a typical, uni-flagellate Herpetomonas. 
