FAMILY M use I DM 



283 



does not gorge itself at a single animal, but nia\' fly from 

 one to another in securing a meal. 



In late years it has come into especial prominence as a 

 a carrier of disease. It was at one time thought to be the 

 carrier of infantile paralysis but this relation has not been 

 substantiated. 



Fig. 227. — Muscina stabulans: a, larva; b, head below; c, head, side 

 view; d, thoracic spiiacle; e, stigmatic plate; /, female; g, head of female; 

 h, mouth parts; i, antenna. All enlarged, d, c, h, i, greatly enlarged. (Bur. 

 Ent., U. S. Dept. Ag.) 



Tsetse Flies. — The tsetse flies have been notorious for a 

 long period as extremely serious pests in parts of Africa 

 and were described by early explorers because of heavy loss 

 to domestic and wild animals. In recent years these have 

 been connected with the transmission of certain kinds of 

 diseases, and are now looked upon as having a most impor- 

 tant bearing from the medical standpoint. 



The species longest known, Glossina morsitans, has been 

 especially connected with loss among cattle, and horses. 

 Glossina palpalis which has been determined as the cause 



