ON THE STRUCTURE OF THE ANTENNAE. 



537 



The minute structure of the antenna can only be satisfactorily 

 studied in thin sections ; those from antennas fixed with 

 osmium peroxide or Flemming's mixture are far the best. 

 The osmium peroxide stains the whole organ and the fibres 

 of the olfactory nerve intensely. 



The cuticular layer of the integument of the third joint is 

 not more than 12 /n in thickness, except near the base on its 

 outer aspect, where it is thicker than elsewhere. Surface- 



FIG. 72. The antennae of Leptis, Tachina, and Calliphora. 



A, the right antenna of Leptis triangularis, $ , Linn. From a cabinet specimen seen 



as an opaque object. 

 Z>, the right antenna of Tachina vulpina $ , Fall. From a cabinet specimen seen as 



an opaque object. 



C, the left antenna of a male Blow-fly seen as an opaque object. 



D, the left antenna of a female Blow-fly, from a compressed specimen, which has 



been cleaned in caustic soda and mounted in Canada balsam. 

 , a portion of the integument of the same seen with a J inch objective. 



views show that it is densely covered with fine curved setae, 

 from 20 jj, to 25 fji in length, with minute transparent dots 



