103 
The larvae of H. muscae and H. megastoma were found 
o possess very similar appearances. H. megastoma was 
usually slightly shorter than H. muscae, possessed a longer 
pharynx and a shorter anterior oesophagus, and the nerve ring 
was situated nearer the anterior end than in H. muscae. Both 
species of larvae possessed longitudinal ridges in the cuticle. 
It is doubtful if these small differences in the appearances 
of the two larvae would prove sufficient for the purpose of 
differentiating larvae taken from granulomata, as in this case 
the larvae usually show some retrogressive changes and exam- 
mation is more difficult. i 
e of H. microstoma were found to be shorter than 
larvae, and the worms undergo their evolution in the pupae. 
When the flies hatch out they are infested with adult parasıt 
which cause paralysis of the proboscis on account of th 
accumulation in this situation. 
T rvae apparently do not possess the power of 
i is of flies. Rupture 
by the larvae, which pressure would be in direct proportion 
to the number of larvae present and their activity. r 
the larvae appear to be capable of penetrating other objects 
Such as filter paper. : : 
arvae do not appear to live in saline solution, horse 
Serum, or water for longer than two or three , and rarely 
a 
as long as seven days. The longevity of the larvae outside the 
