116 
necessity to fall back on such an hypothesis as this. It seems 
possible that S. calcitrans infested with larvae of H. micro- 
stoma may inoculate these larvae into the skin of a horse with 
larvae. 
As far as can be ascertained the granulomata observed 
on the sheath and limbs have not resulted from infection of a 
wound. In no case has there been a history of a previous 
wound. It is possible that small wounds may have been over 
looked, but it must be conceded that the sheath is a very 
_ These granulomata appear about the sheath and limbs, 
sites commonly attacked by Stomozys calcitrans. When one 
wounds into the skin and subcutaneous tissues. 
. Wounds would often present ideal conditions for contam- 
ination by larvae and their subsequent penetration into the 
deeper tissues. It is probable that this method of infection 
does occur, but there seems to be no doubt that it is not the 
only method of infection. _, 
Habronemiasis is so common in horses that it is rare to 
find a stomach free from one or other of the three species 
so, it is remarkable that habronemic granulomata 
and er temperate countries ere are sev Y 
reasons for this: —(1) Z. megastoma is not as common the 
species. It has been suggested that larvae of ge 
the proboscis of flies is n 
dans Tt would appear that the larvae may escape from 
