On Moths and Butterflies. 85 



upon the underside of their wings, which do not appear at all 

 in their larva state, but appear on the angular projections of 

 their pupa cases. 



One of our common moths, the Garden Tiger (Arctia caja), 

 the larva of which is thickly clothed with long black hair, with 

 some whitish ones on the back, and reddish-brown hairs on 

 the sides, in the imago has dark brown fore wings, with white 

 blotches, and the hind wings reddish-orange with six or seven 

 blue-black spots. 



In another species the Cinnabar (Callimorpha Jacobsea), the 

 larva is slightly hairy, black, with orange-yellow or reddish 

 rings around its body, and the moth has its fore wings smoky- 

 grey, with a red stripe, and hind wings red, with black margin. 



Another moth common in our gardens, the large Magpie 

 (Abraxas grossulariata), has its larva white, dotted with black, 

 and reddish-yellow lines on the sides, the moth being white, 

 with rows of black spots and slender lines, and blotches of 

 orange. In this species both larva and moth are very similar 

 in color, and the pupa is again somewhat like being reddish- 

 black with orange rings around its body. Another moth, 

 Stilpnotia Salicis, the White Satin, which is pure satiny white, 

 without any spots, has its larva many colored, white, with 

 black lines, the sides bluish-white, spotted with black and red 

 velvety tubercles. 



Many of the larva of both butterflies and moths have 

 extraordinary forms, some having humps like the camel, 

 others resemble the lobster, some are more or less covered 

 with sharp spines, others thickly or thinly clothed with hairs, or 

 with groups of hairs on their backs in various positions and 

 quantities, but all these curious forms and characters disappear 

 in the final change into the pupa state, and in not one instance 

 do they affect the shape of the moth. 



I could quote many other instances of strange variation of 

 colour, but think these sufficient for my purpose of illustra- 

 tion. The question is — What is the cause or origin of color 

 and variation in the markings of both butterflies and moths ? 

 Has the food-plant anything to do with it ? Experiments 

 have been tried, but with very little success. The larva of 

 the Tiger Moth, which feed upon almost all low growing 

 plants, if fed entirely upon lettuce leaves, will produce pale 

 colored moths, the white predominating over the dark ones, 

 and if others are fed entirely upon the purple cabbage these 

 will produce very dark colored moths, and I have read of 

 some that were nearly or quite black all over. 



As a rule larvae are not easily experimented upon with a 

 variety of food, for with a few exceptions they will only feed 

 upon their natural food-plants, and if these cannot be 



