32 
AMOEBA GHIRONOMI, NOV. SR, PARASITIC IN THE 
ALIMENTARY TRACT OF THE LARVA OF A 
CHIRONOMUS. 
By ANNIE PORTER, B.Sc. Lond., 
Zoological Research Laboratory , University College, London. 
(With 21 Text Figures.) 
The occurrence of an Amoeba in the alimentary tract of the 
familiar “ blood-worm ” or Ghironomus- larva has not been recorded before 
so far as I am aware. Inasmuch as locomotion is effected by means of 
a pseudopodium lying in a definite direction, and as the motion is 
very rapid for a parasite of its class, the Amoeba possesses special 
interest. 
Materials and Methods. 
The investigation of this Amoeba, which I call Amoeba chironomi, 
n. sp., was conducted during November and December, 1908, and 
January, 1909, when material was not easily obtainable. The Ghironomus- 
larvae in which these interesting Protozoa occurred were young forms 
not more than half grown, and were actively engaged in tube formation, 
using the Spii'ogyra and Elodea in the vessel in which they were kept, as 
a basis for the building of their tubes. All the larvae were very 
active. Of those examined about half were found to be infected, but 
in no case was the infection a very heavy one. 
For purposes of examination, the gut of the larva was rapidly 
removed and placed on a glass slide together with physiological 
salt solution at the temperature of the water in which the Chironomi 
had been living. Fresh preparations were so examined. Methylene 
blue was used as an intra vitam stain, and was found of service, 
particularly in observing the contractile vacuole. Encystment was seen 
