SATURNIA PAVONIA. 315 



bred a specimen at Baldock with semi-transparent wings, a large 

 proportion of scales being apparently absent {Ent. Rec, v., p. 105). 

 Frings records (Soc. Ent., xiii., p. 130) the breeding, in April, 1897, 

 of a very pale albinistic $. Gauckler describes and figures {Illus. 

 Woch. fur Ent., i., p. 211, fig. 3) an aberration of S. pavonia that 

 emerged in February, and has the bands which border the ocellated 

 spot of both forewings united {dh. fas data, n. ab.), directly beneath the 

 spot, into a single broad dark carmine-red band, whilst the white area 

 surrounding the ocellated spot has almost disappeared. Dwarfs are not 

 at all uncommon among bred specimens, and Davis notes some from 

 Waltham Cross only about half the normal size. Our smallest $ s 

 are only 50mm. in expanse (ab. minor, n. ab.). Morton, on the 

 other hand, notes ? s from Rothiemurchus Forest that expand 

 73mm.," and some of ours reach 91.5mm. It is difficult to know 

 how far the development of the tint characteristic of one sex, by the 

 other, is a mere matter of individual variation, or an external sign of 

 an internal modification in the direction of gynandromorphism. 

 Pearson notes (/./.) that he has a bred $ with 5 coloration from 

 Wannock ; Hewett has a $ from York, having hindwings 

 approaching the $ coloration; Gregson observes {Ent., iv., p. 13) 

 a very dark $ , and 3 barren $ s approaching the colour of the 

 $ s. Newman records the breeding of a subdiaphanous specimen 

 that had been three years in the pupal stage, and we have already 

 noted (anted, p. 234) that Standfuss has produced dull and 

 ill-marked examples by exposing the pupae to high temperatures 

 and forcing them to emerge in autumn without a winter hybernation 

 as pupae. Frings has produced similar poorly scaled and ill- 

 pigmented examples, by subjecting pupae to a low temperature and 

 lengthening the pupal period. Thus the latter observes (Soc. Ent., xv., 

 p. 35) that 1896 pupae kept out of doors in winter and placed in a refri- 

 gerator during the summer, produced in the spring of 1899, crippled 

 imagines, weakly marked, and very thinly scaled, and thus resembling 

 those that emerged in the spring of 1898 under similar treatment from 

 1896 pupae (loc. cit., xiv., p. 59). . He further notes (Soc. Ent., xiv., p. 

 67) that fresh pupae of S. pavonia, S. spini and S. pyri, were exposed 

 in the summer of 1898, 10 to 15 times, 6 to 10 hours at a time 

 to a temperature of -15 C. They were then placed till late autumn 

 in a refrigerator, hybernated in the open, part only producing 

 imagines in the spring of 1899 ; almost all the S. pavonia were 

 normal, probably only those being aberrant that were exposed to 

 the frost immediately after pupation. These latter are pale in 

 colour with much widened, hardly dentated, subterminal line and 

 with the red of apex often darkened to black ; whilst one very aberrant 

 S has the wings strikingly small and narrow, the expanse when the 

 specimen is normally set (inner margins of forewings forming together 

 a straight line) being only 39mm. ; its ocellated spots only consist 

 of yellow rings in the black area ; the double subterminal line not at 

 all dentate, and so abnormally broad as to reach the eye-spots. 

 Many of these pupae of ,S. pavonia did not emerge till autumn, 

 1899, a fter spending the summer again in the refrigerator. Among 

 these were an aberrant pair, agreeing with those described above 

 and those bred in 1898. Frings considers that these experiments 

 show that, through long-continued moderate cold, and through frost 



