(52 LIFE HISTORY OF HABRONEMA. 



that a similar parasite infested the head region of the 

 Queensland cattle fly, Musca vetustissima, the worm being 

 listed as H. tmiscce in 1914. We have re-exaulined the 

 material, and have found it to be H. muscce. In 1914, 

 H. Tryon (Ann. Rep. Dept. Agricult. Q'land, 1914, p. 116), 

 mentioned the presence of the helminth, Hahronemn sp., 

 in this native fly, and suggested that it might possibly be 

 the larva of " Sjnroj^tera {Onchocerca) Gibsoni." 



In 1916, Bull published an account of a granulomatous 

 affection oi the horse in certain parts of Victoria and 

 South Australia, pointing out that the cause was a species 

 of Habronema in its larval condition, and that the malady 

 was similar to the cutaneous habronemiasiis described by 

 Raillet. He believed that the larvae, which were in the 

 final larval stage, as described by Ransom, were introduced 

 bj^ a biting fly. '' Swamp cancer '" of horses in the 

 Northern Territory was regarded as being a form of 

 habronemiasis, this opinion being opposed by Lewis and 

 Seddon (1914, 1918). 



In 1918, the two last-mentioned investigators called 

 attention to the rather common occurrence in Victorian 

 horses of a habronemic conjunctivitis, but were unable 

 to state which species of Habronema was the cause. 



In the same year the presence of the adult of H. nniscce 

 in New South Wales and Queensland was noted hy one of 

 us (Johnston, 1918, p. 214). Shortly afterwards Hill 

 published an important paper dealing with the life history 

 of the three species of Habronema infesting the horse's 

 stomach, viz., H. muscce, H. megasfoma and H. microstoma, 

 showing that the two former utilised the common house 

 fl}', Musca clomestica, as an intermediate host, while the 

 stable fl}^, Siomoxys calcitrans, was proved to be able to 

 act similarly for H. microstoma. 



