( -xiii ) 
the female; in the wet-season or proterpia form they are 
retained by neither sex, but the under-surface of the female 
is duller than that of the male. 
The simultaneous occurrence in generally dry localities, such 
as Aden, of forms which in other places are associated with 
contrasting seasons, was not easy to explain. Prof. Poulton 
had shown that in several species of Precis the dry-season form 
was larger than the wet, and had on that fact founded the 
inference that the dry-season form must have been predeter- 
mined in the larval stage. But there was reason to believe 
that in many genera, and perhaps even occasionally in Precis, 
the assumption of the characteristic seasonal garb was not 
determined until a later period—in some cases, the last few 
days before emergence from the pupa. If it might be assumed 
that the Aden species in question were in a state so sensitive 
to meteorological conditions as to respond almost immediately 
to a few heavy showers, such as were reported to fall there 
not unusually from January to May, the intermixture of 
“wet” and ‘‘dry-season,” which in many cases meant an 
intermixture of aposematic and cryptic forms, might possibly 
be accounted for. This suggestion could only be verified by 
observers on the spot. 
