80 LIFE HISTORY OF HABRONEMA. 



obtained.'' He believed the accidental swallowing of 

 living or dead infested flies was the means by Avhich horses 

 became infected wdth H. muscoe (p. lo, 23). 



Bull (1916, p. 193) in discussing Habronema larvae 

 ■as the causative agents of certain granulomata of equines, 

 stated that it seemed certain that they were introduced 

 by a biting fly, and suggested Stomoxys as a possible vector. 

 The larvae found in the granulomata in Australia and in 

 the " summer sores "' elseAvhere showed the characteristics 

 of the last larval stage occm*ring in flies. They Avould be 

 accidentally inoculated in such cases during the feeding 

 operations of the fly. 



Lewis and Seddon (1918, p. 92) in dealing with 

 habronemic conjunctivitis of horses in Victoria, referred 

 to the possible infection of the eye by Habronenui larvae 

 depdsited accidentallj^ by some species of fly. 



Hill failed to bring about the escape of larvje from 

 living and dead flies (p. 20, 34) by using moisture and also 

 saline solution. He stated his opinion that the accidental 

 ingestion of both living and dead infected flies jwovided 

 the normal means by which the larva found its ^^ay to 

 the horse's stomach, there to be liberated hy digestive 

 agencies ; in other words, he supported Ransom's con- 

 tentions. He mentioned, however (p. 63), that te had 

 not come across any flies in the 39 horses' stomachs 

 examined, though in 37 at least one species of Habronema 

 was present. He found that heavily-infected Stomoxys 

 flies were not able to puncture a horse's skin. 



Bull (1919, pp. 98, 100, 102) endeavoured, by using 

 sugar solution, to ascertain hoAv the larvae of the three 

 species escape from their hosts. Though a few larvae \Vere 

 liberated, he did not know whether \,\\ey came from living 

 or dead flies, or Avhether there had been any injur}- to the 

 proboscis as a result of handling. From dead flies placed 

 in saline solution, larvae were obtained. He found that 

 Avorms could live in saline or in horse serum for 48 or even 

 72 hours, and for several daj^s in the bodies of dead flies, 

 if loss of moisture were prevented.* The escape from the 



*Our expeiience in respect to these facts was similar. " 



