Variation and aberration in butterflies. 113 



mentioned. This powdering is sometimes prolonged, following 

 the course of the nervm-e that here traverses the wing, almost up 

 to the large white costal patch. 



This striking peculiarity, though in a less marked form, 

 occurs also in one individual between the third and fourth of 

 these five spots. 



Undei' surface. — The most remarkable characteristic of the 

 fore wing is again the widening of the red cross-band. More- 

 over, there occurs with some frequency a red spot in the black 

 ground colour of the region of the wing adjacent to the dorsal 

 border, in the exact situation where, in V. callirrhoe, the red 

 area of the wing projects outwards. 



The hind wings show but little departure from the normal 

 condition; the triangular light spot about the middle of the 

 costal margin is, however, in these warmed specimens, rendered 

 less distinct by a powdering of dark scales. 



b. Cold. 



(1) Thirty-one days in the ice-box, then 8 days at normal 

 temperature. 



Here, as in the warmed specimens of V. atalauta, there is 

 much individual variation. 



The chief reason for this may be that in this species it is not 

 possible to collect large broods from the same parents ; the 

 insects while being reared, even though much material of the 

 tame species is employed, are therefore not passing contempo- 

 raneously in large numbers through the same stages of develop- 

 ment, for which reason it is almost impossible to subject a large 

 proportion of individuals in quite the same stage of growth either 

 to a raised or lowered temperature ; moreover, quite apart from 

 this consideration, the insects, derived as they are from many 

 different stocks, interfere with the experiments by introducing a 

 greater diversity of qualities than would be the case in large 

 broods coming from the same parents. 



U2:)per surface.— The white costal spot becomes enlarged ; the 

 red band of the fore wing is intersected in the middle by two 

 black transverse shades, distant from each other about 1^ milli- 

 metres ; the space between these transverse shades is at times 

 almost completely filled in with black scales. In the same way 

 the lowest part of the red cross-band, on the dorsal margin, 

 usually becomes cut off by a black line which follows the course 

 of the nervure that occurs here [i. e. the first median nervule] . 



In extreme cases the red patch thus cut off on the dorsal 

 edge is almost obliterated by a black powdering. Blue scales 

 are also found between the white costal patch and the red band, 

 and in a few cases on the dorsal margin internally to the latter. 



On the hind wing the black points in the red band on the 

 outer margin diminish in size, and acquire, like the terminations 



