A TREMATODE PARASITE OF THE ENGLISH SPAR- 

 ROW IN THE UNITED STATES. 



By Leon J. Cole. 



UNIVERSITY OF WISCONSIN. 



In early June, 1910, young sparrows (Passer domcsticus) 

 were abundant about the barns and poultry plant of the College 

 of Agriculture of the University of Wisconsin, and it was 

 observed that occasionally certain individuals in the flocks 

 appeared reluctant to take flight, and when they did so their 

 flight was heavy, as if the birds were in some way weighted down. 

 Such individuals frequently lagged somewhat behind the others, 

 and it was often with difficulty that they managed to alight even 

 so. high as the top of a fence. On closer approach it was 

 observed that these birds were hampered by some sort of growth 

 or tumor in the region of the anus, of such size that it was often 

 plainly discernible at a distance of several feet. 



Specimens of these sparrows were finally secured, when it was 

 seen that what had appeared to be a single tumor, was in reality 

 made up of a number of aggregated vesicles or cysts, the largest 

 of which were about 5 mm. in diameter. Upon opening these 

 vesicles, they were found each to contain two, or sometimes 

 more, broadly ovate trematode worms, which were provisionally 

 identified as Monostoma faba Bremser. 1 Figures 1 and 2 show 

 ventral views of two infected sparrows. It will be noted that in 

 Figure 1 the vesicles form a grape-like cluster on the lower 

 abdomen ; 2 in Figure 2 there is a similar bunch in the same relative 

 position, but in addition this bird has a rosette-like cluster of five 

 cysts just below the sternum. The photographs also show on 



1) Professor H. B. Ward of the University of Illinois kindly agreed 

 to examine this parasite, and accordingly specimens were submitted to 

 him. In return he writes: "I think you have the form indicated, but 

 it would be hazardous to make a positive statement without giving more 

 time to the study of the structure than is possible for me at the present 



moment." , . . - 



2) Some of the feathers have been plucked away on both these birds 

 in order that thev might not obstruct the view of the cysts. 



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