132 THE entomologist's record, 



can perfectly stand for the Florence first generation, which, as far as 

 I have made out, is the predominant one over the whole of southern 

 Europe and extends locally also to Northern Africa. Fig. 7, on pi. 

 XXXII. of ilJioj). Pal., gives an excellent idea of its aspect and it is 

 quite identical with many Florentine individuals, although it represents 

 a female from Le Tarf in Algeria. Stauder in his Weitere BeitriUie, 

 describes and figures it from Illyria. The characteristic of grade VI. 

 is the strong tendency to total obliteration of the greater part of the 

 dark pattern, especially on upperside. This is due l3oth to the tone of 

 its colour, which in typical series is constantly pale grey in all the in- 

 dividuals and extremely pale in many, and to the marked reduction in 

 its extent, as compared with the races mentioned in grade V. The 

 basal suffusion is limited ; the nervural streaks scarcely stretch beyond 

 the surface of the actual nervure and are entirely abolished in many 

 individuals ; the apical crescent and the spots are small, the hinder 

 one not unfrequently being obliterated ; the extreme form has been 

 named ab. thn»iiel(la by Stauder from Gorz specimens ; the streaks on 

 undersides of hindwings are thin and of a lighter greenish-gray. 

 These characters are distinctly most prominent in the most dry and 

 warm localities. A series from Milan, in the Turati collection, could 

 well be called race nibjaris trans, ad Kiiiorix, VrtJ^ ; Milan is so much 

 damper than Florence that it produces individuals similar to average 

 uiiiiiris mixed with others, which are quite vnh/aris. My fig. 6 on pi. 

 xxxii. represents an exceptional individual in my series of iiinoris, 

 which by the extent of the pattern belongs to the latter, but 

 by the pale gray tone is similar to vulgar isi. In Florence such 

 individuals are found now and then as extreme variations, overlapping 

 grade V. 



The following, to my knowledge, are not found in Europe, but I 

 must mention them to complete the series of grades we are dealing 

 with : — 



Grade VII. seems to be the result of surroundmgs as bad for this 

 species as it can survive in, on account of heat and drought. It is 

 reduced to meagre dwarfs ; not only is the upperside pattern still 

 more obliterated and paler than in vith/aiis, the little that remains con- 

 sisting in all the males, and in many females, solely in true or trans- 

 verse pattern, but even the streaks of underside are entirely absent on 

 forewing, and are reduced on hindwing to sparse and scattered pale 

 grey scales, scarcely revealing streaks and resembling more, in extreme 

 specimens, those of P. rapae, L. I have described and figured it in 

 FJiop. Pal. under the name of pseudorapae, from a Beyrout, in Syria, 

 series, which I possess. (PI. xxxii., figs. 23 and 24.) 



Grade Vlirt is the most suitable heading I can think of to classify 

 a variation, which is evidently successive to Grade VL, but on a 

 difterent line from the one I have just described as Grade VII. It is 

 here that the variation of the species seems to bifurcate into two col- 

 lateral branches, as it seems to do, although less distinctly, at the other 

 end of the series. In unsuitable surroundings the organic balance of 

 the species gives the impression of becoming unstable, so that it has to 

 modify itself and establish new centres of oscillation of its individual 

 variations by a selection of the individuals more suited to the various 

 localities and just able to survive in them. Instead we can quite well 



