886 



BRITISH BUTTERFLIES. 



grades as "well-developed," "medium," and "slight," and he observes 

 that captured specimens exhibited this grading as follows : 



1. Well-developed tails. — One example from Lindau ; one from Freiburg ; 

 one |rom Berlin (eleus) ; one from Sardinia (first brood) ; eleven from Genoa 

 (second brood, mostly eleus) ; two from Greece (eleus) ; one from Sicily (eleus) ; 

 many from Japan (summer brood) . 



2. Medium tails.— One example from Lindau ; one from Freiburg ; one from 

 Sardinia (first brood) ; one from Greece (eleus 9 ) ; many from Japan (second 

 brood) ; some from Japan (first brood).- 



3. Slight tails. — Two specimens from Lapland ; two from Sardinia (first 

 brood) ; many from Japan (first brood). 



The captured examples show that the tail is more often present in 

 the summer brood and in a hot climate, than in the spring brood and 

 in a northern climate, a conclusion supported by the fact that, of the 

 32 Neapolitan specimens reared at Naples, 80 had them well-developed, 

 and 2 medium, and none had them only slightly. The examples reared 

 from Neapolitan eggs at Freiburg, at a living-room temperature, pro- 

 duced 8 with well-developed, and 13 with medium to slight, tails. The 

 examples from Neapolitan eggs reared like the last, but from pupae 

 placed in a refrigerator, produced 15 specimens with medium to slight 

 tails, and 11 specimens with them entirely wanting. The develop- 

 ment of these structures, therefore, appears, in Weismann's opinion, 

 to be connected with temperature operating during pupal development. 

 Chapman gives (Ent. Rec, xvi., pp. 167 et seq.) some most interesting 

 notes on the variation of this species, more particularly in western Europe, 

 and he records the following general conclusions on some observations 

 made on specimens from various British and extra-British localities, and 

 exhibited at the South London Entomological and Natural History 

 Society : (1) Size : This does not seem to depend on place or season, but 

 on the period spent in the larval state, though there is much variation 

 in any one locality, as temporary strains that are hereditary. There is 

 thus some tendency for the more northern specimens to be the larger, 

 the Lapland specimens examined being amongst the largest. These 

 are also the only certainly single-brooded specimens shown; the species 

 is, however, usually single-brooded in Scotland. The most uniformly 

 small specimens shown are those bred this autumn (1903) at Reigate. 

 These were reared at a temperature not less than 85°F. throughout. They 

 had plenty of food of good quality, and their rapacity and continuous 

 feeding struck one very much, as well as the very few days they took 

 to feed up. Their small size is due, therefore, to rapidity of growth, 

 and not in any way to starvation, development outstripping the possibili- 

 ties of the mere mechanics of eating. Nevertheless, it seems very 

 frequently the case that the eleus form presents very large specimens. 

 The phlaeas form may be small from starvation, having passed the 

 winter as larva, whilst the summer form may have fed up slowly on 

 fine fresh grown food in the cooler early summer, and have only been 

 submitted to an ^/.s-producing temperature when it has reached the 

 pupal stage. (2) Form : There seems considerable difference in the 

 sharpness of the apical angle, the wing looking short and square in 

 some specimens and long and pointed in others. The difference is not 

 perhaps very great, and setting may sometimes exaggerate the appear- 

 ances. Still two specimens from Arcachon and two from Susa that 

 have been selected, seem very pointed, and two from Torre Pellice very 

 square, others from these same localities are otherwise, and one is 



