126 THE entomologist's MCCOKD. 



rare instances in which the more usual form is outnumbered by 

 nitida or alhidice, as stated above. Linnens's description could apply 

 to almost any form of the species ; the habitat he gives is " Southern 

 Europe and Africa " ; the first figure quoted by him is Petiver's ; the 

 specimen left by Linneus with his own label belongs to the form 

 which is by far the commonest in the third generation (see pi. xxx., 

 fig. 3, of Rhnp. Pal.) ; the names subsequently given to various forms 

 by other authors all restrict the Linnean one to this form ; so, there 

 seems to be no doubt possible. I have mentioned in my introductory 

 remarks to these paragraphs on the Pieridoe (page 69) that Eostagno 

 thought all the Pieridi had a partial autumnal generation. Renames 

 za/ielloiiii and describes that of dapUdice as follows : " half the size of 

 typical form ; black spots of upperside less intense and more reduced ; 

 prevalence of the yellow dusting on underside." This was grounded 

 on specimens collected in 1910 by Querci at Formia (Caserta). Since 

 then the latter has made careful observations every year, and be has 

 concluded that those were only laggard weaklings and that daplidice 

 never produces that late emergence even as sporadic individuals. The 

 extraordinarily favourable 1921 did not produce any and has been 

 conclusive. Besides, one might remark that Rostagno's underside 

 character consisting in an abundant yellow colouring is in no way a 

 transition to the spring form bcllidire, but just the opposite, whereas it 

 is quite a rule that the fourth emergence should approach the first in 

 aspect. I conclude that nearly everywhere in Europe there exists 

 only the one race dajdidicc, with : I. gen. bellidice, 0. ; II. gen. 

 e.vpauxa, Vrty. ; III. gen. dajdidice, L. In rare instances the third 

 generation must be named nitida, Vrty., or even alhidice, Obth., as 

 shown by a series from Corsica in the British Mus., and in these cases 

 the entire race should, of course, bear these names. 



I'ieris napi, L. — This is one of the most variable of European 

 butterflies, individually, seasonally and geographically. Much has 

 been written about it by many authors, evidenth' attracted by its 

 striking forms, both Paltearctic and Nearctic. A considerable number 

 of these have been named and discussed at length. The European 

 ones have been dealt with, for instance, by Wagner {Verliandl. zooL-bot. 

 Ges. Wien, 1903), by Eober (Seitz's (Tras^-schiiiett., 1907), by myself 

 {Ehop. Pal., 1908 and 1911), by Stichel (/></. Knt. Zeit., 1908), by 

 Schima [Verhandl. zool.-hot. (res. M'ien., 1910) and single forms have 

 been described by many. The work done, however, has been nearly 

 entirely analytical and it might be pushed on this line considerably 

 further, without achieving any very interesting result. What one feels 

 the want of now are synthetical conclusions drawn from it, enlighten- 

 ing one as to how the various forms stand to each other and fall into 

 a natural classification, as to how many, and by \^hat sort of lines 

 of variation they are produced and then as to their geographical dis- 

 tribution and the part they have in characterising races and generations. 

 To develop these subjects thoroughly would require an enormous 

 amount of matferials and a large monograph. It would be very 

 attractive and, no doubt, it will be done in time by some specialist. I 

 have, myself, devoted much attention to this fascinating species and I 

 have collected quite a consideral)le number of series from all sorts of 

 regions, but I fully realise how far I still am from what would be 



