XLVII 



Moore, Bingham being one of these, while Fruhstorfer goes still much further 

 in this direction and thus bases on supposed seasonal varieties of Satyridae 

 various subspecies. But I am convinced this rests entirely on a misconception 

 even when there may be some substratum of truth. In the same introduction 

 I have already referred to the fact that many observers have noted the so-called 

 seasonal forms side by side at the same time in various districts ; even de Nice- 

 viLLE, according to Moore, admitted that the dry and wet-season forms prevail 

 during their respective seasons, but are by no means strictly confined to them, 

 although at the same time he endeavoured to account for this by the circum- 

 stance that even during the dry season showers of rain occur occasionally and 

 that the wet season is sometimes interrupted by periods of drought, a matter, 

 however, not of so much significance that the fact in question, which, more- 

 over, does not occur now and again only but happens constantly, is to be 

 attributed to this. Nor does this in any way explain how both so-called forms 

 are met with at the same time — by no means of rare occurrence — and is, 

 evidently, based on the erroneous assumption that temporary meteorological 

 influences are to be regarded as the determining cause. According to Fruh- 

 storfer, Dr. Martin noted with reference to the Sumatra form of Ypthima 

 Baldus (Morus Fruhst.) that no dry-season form exists of this but that, never- 

 theless, the ocelli on the under side of the hind-wings are sometimes strikingly 

 smaller than usual. With respect to the Pieridae I have published in the work 

 referred to, some important observations in connection with this subject together 

 with my ideas concerning the origin of the differences here alluded to. My 

 observations on the Java Satyridae fully confirm these ideas. 



As will be further noted when treating the species separately, these alleged 

 seasonal forms are by no means distinctly separated but run into each other 

 through transitions and are, moreover, found frequently side by side. It cannot, 

 indeed, be denied that as regards colour some greater development may be 

 observed during the wet season in many individuals of the same species than 

 is the case during the dry season. But seeing that this is by no means the 

 case in all individuals, nor confined to the different seasons, it is impossible to 

 assume the existence of such well marked dry and wet-season forms, as is done by 

 the above-named entomologists. This difference is only manifested in the manner 

 indicated by me on page XVIII of the introduction to my monograph of the Java 

 Pieridae as regards Calledryas Pomona F. ; in the Satyridae it may especially 

 be traced by a study of the ocelli which are very characteristic in several genera. 

 For this purpose, however, the origin of these ocelli must first be well understood 

 and this is only made possible by the knowledge of the process of colour evolution. 



