210 THE entomologist's RECORD. 



underside of the hindwings, where the features are found which chiefly 

 and more constantly differentiate the second or the second and third 

 generations from the first, and which characterise also more constantly 

 the primary races of the hroader regions, apart from the secondary 

 localised ones I will mention further on. The upperside characters 

 usually follow them, in a general way, but in no way necessarily, and, 

 on the contrary, there are cases, in which the opposite extremes of the 

 variations of the two surfaces are found combined together; for instance, 

 in tii/eliKs, first generation, the underside is very much darkened by a 

 thick dusting, whilst the upperside exhibits the very least extent of 

 dark pattern produced by uipneia ; in emUyssa the reverse occurs, 

 and an underside of the lightest description is associated with heavy 

 black markings on the upperside. The features of the upper 

 surface are much more erratic ; in every series one finds an 

 extent of individual variation, which, especially in the female sex, 

 often covers nearly the totality of that afforded by the species. It also 

 gives rise to an interesting phenomenon, not observed so markedly, to 

 my knowledge, in any other species, iw., to a production of very 

 localised secondary races, distinguished by a single character, which 

 becomes prevalent in a limited area, whilst as a rule it is only one of 

 the many individual variations met with occasionally. I think in some 

 cases one would not be far wrong in calling this phenomenon aberrant 

 RACES, because they consist in an unusual proportion between the 

 individual forms, created by the great increase and prevalence of one 

 form out of many, just as in individual aberrations the usual proportion 

 between the markings and the colours of the wing is altered and one 

 of them invades an unusual extent of wing-surface. I will mention 

 these races presently. With regard to the general seasonal and 

 geographical variations of inetjeia, one can note first of all that, 

 amongst the widespread European species, it is one of the least 

 variable. Altitude does not seem to affect it and in each region one 

 meets with the same race from the mountain tops to the sea-shore. 

 Latitude, too, seems to have a limited effect on it. As far as I have 

 been able to make out' in my present state of knowledge, the first 

 generation is identical from Scotland to Spain and even the very 

 special climate of Palaearctic Africa only produces, as we shall see, a 

 slight difference of tone on the underside, and this not in all cases. It 

 reminds one of the similar lack of variation in the first generation of 

 HiDiiicia iildacas, in which, also, Africa alone produces a washed-out 

 appearance of the underside in race cyrenaica, Turati. What, on the 

 contrarv, affects meyera most distinctly in all its generations are certain 

 reoions. In Corsica and Sardinia it acquires such peculiar features 

 that one would not be surprised if it proved to be a distinct species. 

 In Sicily, the .Balkans and Asia Minor its underside features stand 

 exactly opposite to those of the rest of Europe in the scale of variation 

 of iiidirra, and in Peninsular Italy forms more or less intermediate are 

 quite constant. One wonders what special cause there can be in the 

 S.E. for a marked change of aspect in the generation, which is scarcely 

 affected by the difference between the Scotch and the African climate ! 

 It suggests that heredity comes into play and that the four lines of 

 variation I will presently mention constitute four " phylogenetic " 

 races, w^hereas the races which only differ from each other by belonging 

 to successive grades along these lines are purely " ontogenetic," as in 



