110 Dr. Arthur G. Butler on 



he seems to reverse the order, telling us that he 

 captured A. acrita in the dry season, and referring 

 me to a paper of Mr. Trimen's which distinctly suggests 

 that the slightly marked type (which, by the way, is 

 almost the same as A. pudorina) is the winter form of the 

 species captured by Mr. Marshall during the heavy rain ; 

 and he says that, by quietly ignoring this, I have fallen 

 into the error of confusing local with seasonal variation. 

 If Mr. Trimen's insect were the wet -season form of Mr. 

 Marshall's, he would have followed my original course ; 

 but what he has done is to confound seasonal and local 

 forms. 



Admitting that A. pudorina is probably the extreme 

 dry- (not wet-) season form of the species, the form 

 described and figured by Mr. Trimen may occur with it 

 as its wet-season form; whilst if A. acrita occurs (a? in 

 Nyasaland it undoubtedly does) with A. chseribula, the 

 latter would be the wet-season, and A. acrita, as Mr. 

 Marshall says, the dry-season form. 



From Nyasaland however we receive A. cliseribula 

 (wet-season), A. acrita (intermediate), and A. pudorina 

 var., of Mr. Trimen's plate (dry-season), which shows that 

 in dogmatizing respecting seasonal forms, locality must 

 be taken into account. 



My decision respecting this species throughout its 

 range remains as it was, allowing only for the substitution 

 of " dry " for " wet " ; and Mr. Marshall's assumption 

 that, if I had been correct, he ought to have taken A. 

 pudorina and not A. acrita in Mashunaland is based upon 

 a confusion of ideas between local and seasonal forms. 

 To put the matter briefly : If in any part of Africa A. 

 chssribula does not exist with A. acrita, the extreme wet- 

 season form of the species is not developed in that region, 

 and \i A. pudorina does not exist, the extreme dry-season 

 development of the species is wanting, but this does not 

 alter the fact that these intimately connected forms are 

 all one species. Their differences are all limited to the 

 black apex of the primaries above; the borders of the 

 secondaries vary too much in most species of Acrsea to be 

 relied on, and these variations are not limited either by 

 season or locality. 



Respecting the seasonal forms of Precis (== Jitnonia) I 

 have spoken elsewhere. They may be quite correct as 

 regards Mashunaland ; indeed I had already published 



