FURTHER NOTES ON A TRYPANOSOME. 
119 
Further Notes on a Trypanosome found in the 
Alimentary Tract of Pontobdella 
muricata. 
By 
yiiii'iel Kohertsoii, IVl.A., 
Ciirnct'ie Reseai’ch Fellow; Junior Assistant to the Professor of 
Protozoology in the University of London. 
With Plate h and 5 Text-figures. 
Introduction. 
In a previous paper published in the ' Proceedings of tlie 
Royal Phys. Soc. of Edinburgh/ vol. xvii, No. 3, 1907, an 
account was given of the main features in the life cycle of T. 
raise as it appeared in the leech Pontobdella muricata. 
I could not, however, at that time get clear knowledge of 
the early stages of the infection in the leech, nor could I get 
conclusive evidence that the form appearing in Ponto- 
bdella was really Trypanosoma raite. The following 
observations till in these important gaps, and appear to me 
to make it clear that the flagellates found in such abundance 
in this leech are derived from the skate and form part of the 
life cycle of T. raiae. 
I have also taken the opportunity afforded me by a fresh 
set of infected leeches of again working through many of the 
stages in that host. On this occasion I have abandoned the 
Giemsa method and the dry fixation of the films, and have 
used instead such fixatives as Schaudinu’s fluid, Hermann 
