206 Mr. J. W. Slater on the 



Some striking instances of this association of a poison- 

 ous diet with a conspicuous coloration may be found 

 among the larvae of the hawk-moths. Of these there are 

 three species — Deilephila Galii, Nicea and Eu-phorhia — 

 which feed upon different species of Euphorbia, all con- 

 taining an irritant poison. The caterpillars are very 

 conspicuous in their coloration. Thus D. Nicea, when 

 young, is of a light green, with rows of black spots, those 

 of the two central series having each a yellow pupil. 

 After the fourth moulting the green turns to a vinous-red 

 and finally to a reddish-grey, whilst the yellow spots 

 become orange. Few caterpillars are better adapted to 

 catch the eye of every passing bird. 



D. Euphorbice, the spotted elephant, is equally striking. 

 Its ground colour is a glossy black with a number of small 

 yellow dots arranged in belts. Down the back runs a 

 narrow bright red line, on each side of which are two rows 

 of large spots, yellow, white or reddish. The head, feet, 

 and the base of the tail-horn are of a bright red. 



D. Galii, the madder-hawk, has a bronze-green ground 

 colour, with a yellow dorsal line, large round yellow spots 

 bordered with black along its sides, and a red caudal honi. 

 In short, it would be difficult to point out three equally 

 conspicuous caterpillars in the European fauna. It may 

 be said that the caterpillar of the madder-hawk feeds also, 

 as its name implies, upon madder and bed-straw, which 

 are certainly not poisonous. They contain, however, a 

 nauseously bitter principle; and further, this caterpillar 

 is, of the three just mentioned, the least striking in its 

 appearance. It must further be remembered that these 

 caterpillars grow to the length of nearly three inches, and 

 to a proportionate thickness, and that the Euphorbite 

 grow not in. woods or thickets, but in open sandy plains 

 and at the side of field-paths where the vegetation is very 

 scanty. Their stems are slender and their leaves narrow, 

 so that for caterpillars of such size and colour there is 

 absolutely no concealment. I once lived for two seasons 

 at a locality in Upper Silesia where D. Euphorbice was 

 exceedingly common, and during the months of July and 

 August I could often distinguish the caterpillars at a 

 distance of six or eight paces, and how they could escape 

 the observation of birds I cannot imagine. Hence I think 

 it may be safely inferred that these caterpillars are spe- 

 cially protected, either by an offensive odour, a bad 



