SEASONAL POLYMORPHISM. 



69 



All the rieriduc have been left iu an equally sad state of neglect foi 

 years, as compared with many much scarcer species. Since that time 

 both Querci and I have devoted much attention to this interesting 

 family and much light has beea cast on the subject both by us and by 

 others. Turati, in 1910, in his Note critiche nulla Pieris eriicnic, H.G. 

 [Atti Soc. Ital. Sciense Nat., xlix.] gave a lucid account of the three 

 generations of this species. Rostagno, in 1911, in his Rhopulocera 

 Faunae Romanae, Addenda [Bull. Soc. Zool. Ital., xii.] attempted to 

 establish that all the Pieridi had three generations in Rome ; he made 

 the mistake, however, of mixing up the second and the third genera- 

 tion into one, so that he never saw their distinctive features ; he also 

 started from the preconceived idea that all these species had what he 

 called a third generation in October (in reality the fourth, when it 

 exists), so that in the case of dapUdice, of napi, and of enjanc, which do 

 not produce it, he actually described its features from a few laggard 

 weaklings of the preceding. Stauder, in 1913, in his Weitere BeitriUjc 

 zur Kenntniss der Makrolepid. der adriatisclwn Kuatenciehiete [Bull. Soc. 

 Adriatica di Seienze yaturali, xxvii.] , gave an excellent account of the 

 three principal broods and of their features in several Pieris and in 

 Colias croceus ; he entirely overlooked, however, the fourth emergence. 

 I had not read this paper when in 1919 I published in this Journal 

 (vol, xxxi. ; The various modes of E»ien/ence, etc.), the conclusions I 

 had reached by my own observations in Tuscany and by the long and 

 patient researches of Querci in Central Italy. We were very interested 

 to learn subsequently that they exactly confirmed Stauder's. In my 

 Nuove osservazioni sui Lepidotteri PiOjialocerl dell'Isola d'Klba in the 

 Bull. Soc. Ent. Ital., xlviii., p. 180 (separatum distributed in December, 

 1916), I pointed out the features distinguishing the two summer 

 broods of P. rapae, L. In this Journal, of May, 1919, I did the same 

 in C. croceus, P. daplidice, P. vianni, and M. brassicae, as we shall see 

 more at length. Finally, also Rocci devoted some attention to this 

 subject and made some interesting observations in the neighbourhood 

 of Genoa : Osservazioiii sui lepidotteri di Liijuria (Afti Societa Liipistica 

 di Seienze Nat. e Geofjr., xxx., n. 1, of vi'hich I received the separatum 

 on the 8th of April, 1919, and n. 4, received in 1920). In the first of 

 these papers he deals with the Pieridi, but unfortunately he overlooks, 

 like Rostagno, the existence of two summer generations and confuses 

 their characteristics ; he describes well, instead, the fourth generation 

 of brassicae and of rapae, although he, of course, calls it third, and in 

 his second paper that of Colias croceus. 



We thus see that to get to a tolerably clear knowledge of the 

 number of broods and of their features it has required several years 

 and the work of many. What I intend doing here is to collect and 

 summarise the main lines of it, correcting some mistakes of the past 

 and adding a few notes at the same time. I will not deal with the 

 species which do not produce a complex seasonal polymorphism. On 

 the contrary, I will have to devote special attention to Lej^tosia sinapis, 

 L., because this species has been entirely neglected by the writers 

 mentioned above. 



Gonepteryx rliauini, L., and cleopatra, Tu. — Mr. J. A. Simes 

 published in the Knt. Uec. of November 15th, 1920, a very interesting 

 paper on the careful observations he has carried out in several localities 



