74 PROBOSCIS OF BLOW-FLY 



open channels, which suggest an arrangement 

 for the passage of fluids. 



From the observations of Doctor Anthony 

 these ' pseudo-tracheaB ' are suctorial organs, 

 which can take in liquid alike at their ex- 

 tremities and throughout the whole length of 

 the fissures. These fissures may be closed in 

 and thus form complete tubes. This of course 

 implies a voluntary power on the part of the 

 fly which extends to microscopic areas. 



The original photo-micrograph from which 

 the illustration (Fig. 16) was taken, shows an 

 amplification of 100 diameters ; the time of ex- 

 posure was 16 minutes ; the focal distance was 50 

 inches, and the objective used was the half-inch. 



In the second illustration (Fig. 17), the 

 original amplification is 1,000 diameters; the 

 focal distance was 46 inches ; the eye-piece of 

 5 diameters and the |th objective were used. 



Eggs of the Fly. 



There are several genera and species of flies 

 that are common in our houses, either habitually 



