Xlll 



Eyes small. No arista on 

 Four millimetres long. 



(&) Genus Melophagus. 



Wings extremely minute, 

 antennae. Claws bidentate. 

 M. ovi is the sheep ' tick.' 



(c) Genus Ornithomyia. 



Wings large. Four millimetres long. 

 0. aricularia. Occurs on birds. 



(d) Genus Lipoptena, e.g., L. cervi on the red deer. 



(e) Genus Stenopteryx, e.g., S. hirundinis of the swallow. 



J "f HiUolosca Tufnlies. 



Fig. 99 



2. — Nyctcribiidae. 



Found on bats. They have no wings. 



FLEASt 

 Fleas, or Siphonaptera, are considered to be aberrant forms 

 of flies, and hence follow naturally after the division Pupipara, 

 of the flies. 



Life History 



Eggs : About a dozen are laid, in floors, in cracks, etc. ; 

 sometimes in the hair or fur of animals. They are 07 by 0'4 

 millimetres (P. irritans). The eggs hatch in about a week or 

 more. 



Fig. 100. Larva of a Flea x 20 (after Railliet) 



•j- Rabinowitsch has obtained positive results in the transmission of the rat 

 trypanosomes by fleas. In this case, and in the case of Glossina there is no evidence 

 to show that the trypanosome undergoes any developmental change ; nor, even in 

 the case of Glossina, has it actually been shewn that trypanosomes occur in or on 

 the proboscis during the biting of an uninfected animal. 



