VARIATION IN VANESSA URTIC^. 311 



spots show a similar tendency. This sort of development — very 

 different from that in ab. lima (see antea, p. 223, fig. 1), which 

 presents quite another aspect with its isolated crescent — points 

 out the possibihty that a continuous blue hand might border the 

 wings. I beheve that such a variety (if it does not exist 

 ah'eady '?) could soon be hred by pairing some of the transitory 

 specimens obtainable from wild larvae. I would mention here 

 that normal British V. io, male and female — as, for instance, 

 they are figured from photographs in Mr. South's ' Butterflies of 

 the British Isles' — have a black-hlue spotted margin at the apex 

 of the fore wings, as in urticcB, but that a variety may some- 

 times be ca[)tured in which these blue spots spread and form an 

 unbroken blue band with black outer border (see figures of V. io, 

 2 and 3). 



Climatical (Seasonal) and Local Variation in Vane<sa io, L., and what it tends to. 



Cold induces an urticcc-form facies ; heat and contrasts in temperature 

 (cold nights and hot days, cold winters and hot summers), on the other hand, 

 bring ocelUformitij near perfection, and efface all resemblance to urtica;. 



Fig. 2, induced by comparatively cool seasons, is the normal form of 

 V. io in tue British Isles. Fig. '6, induced by hot seasons, occurs with many 

 transitions to Fig. 2 as a variety in Britain, but is, on the Continent, the 

 most common form in many localities, especially in the South, where V. io 

 is often double-brooded, and is therefore often figured as typical in Conti- 

 nental butterfly books. Fig. 1 is V. io ab. fisclieri, Stdfss., induced by cold 

 (temperature experiment representing exaggerated seasonal injlnence) ; it 

 exhibits the ocellus disintegrated into its constituent parts, with a complete 

 chain of luarginal lunules as in var. iclinusa, the local heat form of V. 

 ■urlicce. This form, obtained under such conditions, is, however, only an 

 exaggerated form of Fig. -'?, which latter often exhibits traces of the median 

 marginal lunules, and is a common form in the field wherever the summers 

 are cool and the climate generally contrastless. Fig. 3, with the perfect 

 banded ocellus (as in the peacock's feather) on the fore wings, seems to 

 represent the culminating point of ocelliform development in V. io ; also 

 the hind wings show a fine blue ocellus. But this latter ocellus seems still 

 capable of an exaggerated development, as shown in Fig. 4, induced by 

 exposure of the pupie to tropical warmth for three days, in which the re- 

 maining black bar is suffused with blue. This ocellus contains three small 

 white spots, correlated, evidently, with those of the fore wings. For the 

 latter imusual and beautiful variety (Fig. 4) I suggest the varietal name ab. 

 splendens. Figs. 2, 3, and 4 were bred by me from wild Hertfordshire larvae 

 last July and August. Fig. 1 was bred by Prof. Standfuss by exposing the 

 pup* to a low temperature (c/. Standfuss, ' Handbook of Palasarctic Lepi- 

 doptera,' 1896). The very large local (heat) form of Sardinia. V. io ab. 

 sardoa, Stand., exhibits variation of the groundcolour instead of the ocelli. 



