197 



JOTTINGS FROM THE BIOLOGICAL LABORATORY 

 OF SYDNEY UNIVERSITY. 



By Professor William A. Haswell, M.A., D.Sc. 



No. 16. Note on the Occurrence of a Flagellate Infu- 

 soRiAN as an Intra-cellular Parasite. 



Ill an undescribed Rhabdoccele Turbellarian found in water 

 obtained from a pond in the Victoria Park, Sydney, a remarkable 

 phenomenon was observed. All the specimens examined had a 

 dull yellowish-green colour, and, when they were examined under 

 the compressorium, the colour was found to be due to the presence 

 of innumerable, actively-moving, parasitic organisms. These 

 were situated in the interior of the unicellular glands or other 



large cells in the parenchyma — a very large proportion of these 

 cells being thus infested. When, by dint of crushing the 

 Turbellarian, the parasites were set free from the interior of the 

 cells, their form and movements could be more readily observed. 

 In shape they were nearly always constantly varying with great 

 rapidity between an extreme of elongation and an extreme of 



