ON THE STRUCTURE OF THE ANTENNZ:. 587 
The minute structure of the antenna can only be satisfactorily 
studied in thin sections; those from antennze 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 w in thickness, except near the base on its 
outer aspect, where it is thicker than elsewhere. Surface- 
Vic. 72.—The antenne of Leptis, Tachina, and Calliphora. 
A, the right antenna of Leptis triangularis, ¢, Linn. From a cabinet specimen seen 
as an opaque object. 
4, the right antenna of Tachina vulpina g, Fall. From a cabinet specimen seen as 
an opaque object. 
C, the left antenna of a male Blow-fly seen as an opaque object. 
XD, 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 } inch objective. 
views show that it is densely covered with fine curved sete, 
from 20 « to 25 m in length, with minute transparent dots 
