( xvi ) 



neither of whom, however, thought that the dimorphism thus 

 shown had any relation to the seasons. On the other hand, 

 Batchelor had found that in Queenshxnd the two correspond- 

 ing forms were associated with the summer and autumn 

 season respectively. Similarly, Catopsilia gnoma, Fabr., could 

 not be separated specifically from C. pyranthe, Linn. In this 

 case de Niceville not only held the view of their specific 

 identity, but also allowed that for part of their range C. 

 pyrantlie was associated with the wet season, and C. gnoma 

 with the dry. Tliis raised a presumption in favour of the 

 accuracy of Batchelor's observation with reference to C. 

 pomona. An objection that had been brought on the score 

 of the different habits of C. pomona and C. crocah could not 

 be taken as valid, for analogous differences of habit existed 

 in the case of Precis sesamt's and P. octavia-natalensis, which 

 had been absolutely proved to be the same species. Alto- 

 gether, though the direct proof which would be afforded by 

 breeding one form from the other was still laclcing, the evidence 

 as to the respective specific identity of these forms of Catopsilia 

 was very strong, and the presumption as to at any rate some 

 correspondence with seasonal conditions was hardly less so. 

 On taking a wide view of the question, it became evident 

 that many forms, either known or reasonably supposed to 

 be "seasonal," varied considerably in their relations with 

 meteorological conditions. It was not unusual, in some 

 localities, for the so-called "wet" and "dry" forms to be on 

 the wing together in good condition. Examples of this were 

 numerous in the genera Teracolus and Terras. This was no 

 doubt due, in some cases, to a mere " overlapping " at the 

 change of seasons, but there were well-attested instances of 

 the simultaneous occurrence of diverse " seasonal " forms 

 during the entire period of flinht of the species. On the 

 whole it seemed that in many moist districts, such as the 

 equatorial region of West Africa, the " wet-season " forms 

 preponderated ; while such forms were rare in some drj- 

 districts such as Scinde. But in other dry spots, like Aden 

 and Karachi, there was much evidence to show that all the 

 seasonal forms of certain species occurred together. A well- 

 marked alternation of forms did not take place unless there 



