113 
There seems to be little doubt that the larva present in 
the lesions belongs to the genus Zabronema. 
à In tracing the evolution of these tumours from the earliest 
recognizable lesion, and taking into consideration their situa- 
larvae are capab grating in the subcutaneous tissi 
for some little distance from the point of entry, this migration 
is very limited, an larvae are soon s unded by leuco- 
All the larvae found in the tumours have presented the 
same appearances, and must be regarded as being of the same 
stage of development. There is nothing to suggest that the 
vae have passed through any developmental stages in the 
tissues of the horse. 
mental conditions; H. megastoma has the same life-history as 
useae ; 3 i 
vetustissima in Queensland, so it seems possible that these 
es may be capable of ing through their 
Stages in other flies, particularly Muscids. Nothing, however, 
