66 THE ROYAL SOCIETY OF CANADA 
by membranes. In some cases, about twelve per cent., the kineto- 
nucleus is double, each part being surrounded by a separate membrane 
(Pic. 1B). 
If the foregoing description be compared with that of Laveran 
et Mesnil (:02) for Trypanoplasma borreli it will be found that the 
parasite of the sucker possesses all the characters described for T. 
borreli. It has therefore been assigned to this species. Additional 
evidence on this point will be obtained when it is determined whether 
or not the carp in the Georgian Bay harbour 7. borreli. Efforts are 
to be made to determine this. 
The sucker in which this parasite was found was sluggish and al- 
lowed itself to be easily picked up in a dip-net. It was brought to 
the laboratory in a pail and when taken out of the water to be examined 
died quickly. When examined no external or internal lesions were 
found, but the fish showed an anaemic condition. There is not 
sufficient evidence to show that the trypanoplasm was a cause of 
this anaemic condition. However Trypanoplasma borreli is known 
so cause such a condition in carp in captivity (Mariane Plehn : 04, 
p. 175 and Keysselitz :06, p. 15). 
The occurrence of this trypanoplasm in the sucker is of importance 
as showing the possibility of its having been transferred to this fish 
from the carp which has been introduced into the Canadian lakes and 
occurs not far from where the sucker was caught. The case is also 
important in showing the possibility of 7°. borreli causing a pathogenic 
condition in a fish in the wild state. There is a further interest in the 
occurrence of what appears to be a parasite of European fishes in 
Canadian waters. 
B. Myxosporidia. 
a. Myxidium lieberkühni, Butschli. 
This parasite was found in the urinary bladders of each of the 
three pike (Lucius lucius, L.) in which this organ was examined micro- 
scopically. It appeared to be non-pathogenic. In one case it was 
very abundant, the walls of the bladder being completely covered by 
attached myxosporidia. 
The myxosporidium varied greatly in size, reaching a length of 
170u. It may be elongate, branched, piriform or round. As seen in 
fresh preparations the ectoplasm is without granules, and shows at 
times numerous fine processes (Fig. 2,e). In prepared sections of the 
urinary bladder the parasite was found attached to the epithelial wall 
of the bladder (Fig. 2, g-i). The endoplasm in fresh preparations 
