_ Researches on Insect Flagellates introduced into Vertebrates. 145 
cold-blooded vertebrates is comparable with that of certain try- 
panosomes, such as 7’. brucei and T. lewisi, which are inoculable 
into such animals as snakes, lizards and frogs. 
It may be added that we have consulted the work of Rocha- 
Lima (1912) on Blastomycetes. We find that the parasites seen 
__ by us are not so numerous as those described by him, and differ in 
_ morphology and in bio-chemical reactions, so that they could not 
_ be mistaken for yeast-like organisms. 
V. Significance. of Hxperimental Results. 
This subject has already been briefly discussed in our former 
paper (p. 44), when the zoological importance of the herpetomonad 
cultural stage was indicated, the finding of a herpetomonad in 
man by Franchini was noted, and we suggested that canine Kala- 
azar is really a herpetomoniasis (or leptomoniasis) due to H. cteno- 
cephalt. 
Other points of interest may be considered. From the recent 
publications of a few observers it is now clear that herpetomonad 
stages of Leishmania may be found in man, at any rate in infections 
with L. tropica. The recent observations of Sergent, Lemaire and 
Senevet (1914) have demonstrated the presence of a herpetomonad 
flagellate in cultures of the blood and organs of geckos obtained 
from areas in Algeria in which oriental sore, due to L. tropicu, is 
prevalent. Phlebotomus flies, which may harbour a natural herpeto- 
monad, feed on the geckos and on men. Hence animals like 
geckos may act as reservoirs of leishmaniasis, though Laveran has 
just recorded his lack of success in attempts to infect geckos and 
green lizards experimentally with Leishmania tropica. Lindsay 
(1914) writes that the parasite of dermo-mucosal leishmaniasis in 
Paraguay is believed by native sufferers to be conserved in rattle- 
snakes, and spread by ticks or flles (Stmuliwm) feeding on the 
reptiles and transferring the parasite to man. 
Our experimental results show that there is ground for these 
hypotheses. We find that insect flagellates belonging to the 
genera Herpetomonas and Crithidia have produced infections not 
only in mammalian hosts, like mice, but also in cold-blooded 
vertebrates belonging to the Pisces, Amphibia and Reptilia. 
Furthermore, the flagellates are capable of assuming resting, 
encysted, postflagellate stages in these hosts. 
Regarding the possibility of mice acting as reservoirs of 
herpetomoniasis (ieishmaniasis) in nature, we would draw atten- 
tion to an observation by Dutton and Todd published in 1903. 
This observation has apparently been overlooked, though Todd 
has recently changed his view on the matter. These investigators, 
10—5 
