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THE YOUNG NATUBALIST, 



colour, such as Arge Galathea, Lyvana, Corydon, L. Adonis, and numbers of 

 Geometrce, in which a clear chalky white takes a prominent place. Pierk 

 Daplidice is much more brilliant in colour in the south of France than in 

 England or Sweden. In the Isle of Portland Larentia olivata is of a much 

 lighter shade than usual, and in hot summer weather yellowish examples of 

 Pieris rapce are of frequent occurrence. 



Boarmia repandaria, in England, frequents trees, and when at rest its 

 colour assimilates to that of their trunk ; but in the Outer Hebrides, where 

 there are naturally no trees to rest on, the insect has become differentiated 

 to the colour of the gneiss rock. 



Those species whose larvse feed on lichens, and are often found in orchards, 

 are invariably of a green colour, such as Bryophila perla, B. glandifera, 

 Cleora lichenaria, Leptogramma liter ana, Gracillaria sulphurella, &c. The 

 species, I believe, vary from a darker to a lighter shade, according to the 

 situation of the lichens. Plants possessed of resinous or rather strong vege- 

 table properties may be said in general to produce dark or reddish-brown 

 moths, such as Trachea piniperda, Boarmia abietaria, B. cinctaria, and the 

 genera Thera and Retinia. Most of the marsh moths, and those whose larvee 

 feed on reed and other plants growing in water, are either of a white or 

 straw colour. Take for instance the genera Nonagria, Leucania, and Chilo, 

 and also Macrogaster arundinis, and the Hydrocampidce, 



No better illustration of the assimilation in colour, of the larva to its food 

 plant can be found, than in that of Pterophorus galactodactylus. It feeds on 

 the leaves of the burdock, always being found on the underside, and is fre- 

 quently overlooked by the inexperienced eye. 



Melanic varieties occur very commonly in Ireland, Isle of Man, Scotland, 

 Durham, South Lancashire, and the West Eiding of Yorkshire, The New 

 Eorest is also prone to produce melanic forms, where the soil is in places 

 extremely dark coloured, induced, doubtless, by the abundance of astringent 

 vegetable matter, tannic or other acid, which through the annual decay of 

 large quantities of oak, common bracken, and heath, is set free, and washed 

 into a soil charged with iron, and producing an inky blackness of earth. The 

 localities where we find melanism most pronounced, viz. Yorkshire, Lancashire, 

 and Durham, are all manufacturing districts, where immense volumes of 

 smoke are constantly given off from furnaces and coal pits, covering more or 

 less the whole of the vegetation with a fuliginous deposit, giving to large 

 tracts the name of the black country. 



Species of Lepidoptera which occur during the dark winter months are 

 invariably of a dark colour, as Pcecilocampa populi, Expate gelaletta, &c. 



Satyrut davus is of a far lighter shade in the Shetland Isles than on the 



