48 BRITISH LEPIDOPTERA. 



transverse band also varies, from a narrow line to a wide band that 

 may spread to the outer margin of the wing, and offers a basis of 

 variation for a great number of local forms, which are often further 

 specialised by a marked increase or decrease in size. Some of 

 these local races are further remarkable for the fact that they show 

 more or less constant peculiarities in their life-histories and fixed 

 characters in their larvae, the whole tending to make the working 

 out of the special features of some of these races exceedingly difficult. 

 The vars. sicula, callunae, ?neridionalis and vihirm are especially interest- 

 ing, and Warburg and Bacot have done much good scientific work in 

 crossing these and other extreme forms with each other and with the 

 type. The most remarkable of the colour aberrations is probably that 

 which Cockerel! named ab. olivacea-fcisciata. The difference in size, 

 too, is sometimes very remarkable. Breyer figures (Ann. Soc. Ent. 

 Belg., vii., pi. iii., fig. 2) an aberration with much narrower fore- 

 wings than is usual, and this he considers to have been caused by 

 insufficient nutrition. As to the effect of food on the size of this 

 species, the following notes by Fuchs are interesting. He states 

 (Stett. Ent. Zeit., xli., p. 120) that he attempted to rear a winter 

 brood on pine, and, for this purpose, obtained a number of larvae 

 from birch after they had commenced to hybernate in the autumn 

 of 1866, that he brought them into a warm room, and placed them 

 on pine, after which two moulted and went on feeding, one pupating 

 at the end of January, 1867, the other in the middle of February, 

 the imagines appearing on February 25th and March 25th after pupal 

 periods of four and six weeks respectively. Compared with the local 

 (Lower Rheingau) form, these specimens were fairly normal in size 

 (wing of $ 28mm., 2 35mm.), the pale transverse bands narrowed on 

 all the wings, and sharply cut off from the ground colour. Bieger 

 also experimented (Ent. Nachr., viii., p. 244) in the direction 

 of rearing the larvae of L. querctis on pine-needles. The larvae 

 hatched in the middle of August, and the three first stadia had 

 their ordinary course, the moults taking place September nth and 

 24th and October 10th, bringing them to the normal hybernat- 

 ing stage. He wanted to force them indoors, but they persisted in 

 forsaking their food and laying up for hybernation, so he let them 

 have their way and placed them in the cold. At the end of Febru- 

 ary they were brought indoors again, and on March 10th certain 

 individuals had reached the last stadium, and he concluded that these 

 must, therefore, have moulted a fourth time in autumn. The last 

 did not reach the final stage till April 16th; by May 14th all had 

 pupated, and imagines appeared June 22nd to mid-July. The $ s 

 scarcely differ from the ordinary form of this sex ; the $ s all have the light 

 basal spot on the forewings, which, he says, is wanting in specimens 

 from hybernated pupae.* The basal area of the ? , both on the fore- 

 wing and hindwing, has an angular bend, and is considerably redder, 

 especially on the hindwing. The $ s resemble those of callunae as 

 received from Staudinger, whilst the $ s from hybernated pupae from 

 ordinary food-plants are, on the whole, darker. Our British v;ir. callunae, 

 which usually feeds as a larva from the June of one year until the 



* This, of course, is not generally the case. Most (if the imagiues of var. callunae 

 have this basal spot, although hybernating as pupae 



