NATURAL ENEMIES 73 



Other observers have studied this parasitic worm, 

 which is now placed in the genus Habronema. Hewitt, 

 in England, after dissecting many hundreds of flies, 

 found only two specimens of this parasite. He feels 

 certain that the one found in England is the same as 

 the one found by Carter in India. 



The same species occurs in the United States and 

 has received some attention from Dr. B. H. Ransom, 

 of the Bureau of Animal Industry of the U. S. De- 

 partment of Agriculture at Washington. Doctor Ran- 

 som has very kindly given the writer the following 

 note, hitherto unpublished, which is sufficiently interest- 

 ing to print in full : 



"Referring to Habronema musca, this parasite seems 

 to be very common in the house fly. Out of thirty- four 

 flies examined between June loth and July nth, most 

 of them caught in the laboratory of the Zoological Di- 

 vision, the remainder bred from horse manure obtained 

 at the Experiment Station of the Bureau of Animal 

 Industry, Bethesda, Md., nine were infested. The 

 number and distribution of the parasites in these nine 

 flies were as follows : 



1. Five in the proboscis. 



2. Six in the head and proboscis, one in the thorax. 



3. One in the head. 



4. Two in the head. 



5. Five in the head. 



6. Two in the head. 



7. One in the head. 



8. One in the abdomen. 



9. Two in the thorax. 



