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XXV. 



Notes on the peculiar habits and changes which 

 take place in the larva and pupa of Papilio 

 Nireus. By Mrs. M. E. Barber. Commu^ 

 nicated hy Charles Darwin, M.A., F.R.S., 



^c 



[Read 2nd November, 1874.] 



Papilio Nireus, Linn. A large and handsome species. 

 " Expands 3 in. 6 lin.— 4 in. 3 lin. Eich velvety-black, 

 with bluish-green stripes and spots." (E. Trimen, Eho- 

 palocera Africa? Australis.) This butterfly is common in 

 most parts of the Cape colony. In its imago state the 

 ^ovfevs of Plumb ago Capensis are its favounte resort. It 

 frequents orange trees, the larva feeding upon the leaves 

 of that plant, and also upon those of an indigenous forest 

 tree ( Vepris lanceolata, El. cap. i. p. 447). In colour 

 the caterpillar of P. Nireus closely resembles that of the 

 leaves upon which it feeds, being of a dark green upon 

 the orange tree, and of a lighter green upon the V. lan- 

 ceolata. The pupa (of which I send you a drawing) may 

 be found among the leafy twigs of its food-plant, or upon 

 those of some neighbouring tree ; its usual colour is green 

 (PI. IX. fig. 1). The drawing, however, goes to prove that, 

 under peculiar circumstances, the caterpillar has the power 

 of assimilating or altering its common colour, following 

 suit, as it were, to any locality in which, by accident or 

 otherwise, it may have been placed. 



During the months of March and April I succeeded in 

 rearing a number of these caterpillars. They were placed 

 in a case with a glass cover ; the case was partly made of 

 wood, and partly of brick. The colour of the wood was 

 a dullish-yellow, that of the brick a purplish-brown (figs. 

 3, 4). In the case I had previously placed a branch of 

 the common bottle-brush shrub; its leaves had become 

 partly dried, and were of a pale-green colour. 



The caterpillars were fed upon orange leaves, and ap- 

 peared to thrive well; they were fine, lively, well-con- 

 ditioned specimens of their kind ; they had fresh leaves 

 supplied to them every morning, and, in fact, had nothing 



TR«x«. VNT. SOC. 1874. — PART IV. (dec.) 



