DISTRIBUTE INSECT VARIETY. 289 



the close approximation in shape and colouring of the scale wings, 

 the better marked forms and scientific types in a state of nature 

 recognise and freely cross with their aberrations; and in the 

 case of melanism, Mr. Llewelyn has found that the result of 

 breeding in is to increase the number of blackamoors. Thus 

 from a dark Welsh female of the geometer Tei^hrosia crepuscu- 

 laria, the offspring in the first generation were one-half dark 

 and one-half pale. In the second batch, the produce of dark 

 parentage, they were dark in the ratio of two to one, and the 

 third generation from these negroes were alike dark."^ 



It is interesting to inquire in what way the colouring matter 

 is imparted to the wings by the glands as they lie beneath their 

 chitineous pupal covers previous to expansion ; for then it is the 

 pattern is impressed — extension of parts subsequent to exclosure 

 merely serving to elongate the markings and enlarge the design. 

 This it would seem can happen only in two ways, in either as there 

 is a prepossession : the secretory matter must flow from the thorax 

 through the tissues of the flaccid wings, or its stains are im- 

 pressed by their membranous coverings in the manner of a 

 printing-press. That the latter hypothesis is not wholly ground- 

 less, it may be mentioned that a specimen of the nocturnal moth 

 Leucania conigera, captured near the Welsh Harp Tavern, to 

 the noi-th of London, in 1877, was found to have the markings 

 upon the upper wings reproduced on the upper surface of the 



* Figures of our insular varieties of moths and butterflies will be found in 

 the An. and Mag. Nat. History, Newman's " Brit. Butterflies and Moths," 

 and the Entomologist. Many coloui-ed figures of Continental varieties are 

 scattered through German works, but the most valuable reference to the varia- 

 tion of Lepidoptera on PalEearctic areas is doubtless Staudinger and Wocke's 

 " Catalog de Lepidopteren des Eui-op£eischen Faunengebiets. " Dr. Staudinger 

 remarks on insect kinds as species, chance variety or aberration, local varieties, 

 or varieties of race, Darwinian varieties, and seasonal varieties ; variation due to 

 soils, altitude, and other causes, is also noticed. This work will more fully 

 illustrate those few observations I have here recorded from British sources. 

 Thus the Scarce Swallow Tail has a pale southern variety ; the Clouded Yellow 

 Palasno, a pale northern one. The female of the latter on the Alps is some^mes 

 yellow like the male, and here the brown female of L. Corydon becomes some- 

 times blue like its male. Another Blue Butterfly is pale on the limestone 

 mountains of Spain. Certain Hair Streaks have longer tails in Asia Minor, 

 and species vary everywhere in wing expansion and colour according to certain 

 laws. As regards variation of Lepidoptera on Neartic areas see " The Butterflies 

 of North America," by Wm. H. Edwards, &c., &c. 

 T 



