the colours of certain Lepidoptera. 485 



Explanation of Plates XIV. & XV. 



PLATE XIV. 



All the figures are drawn of the natural size, wliicli in all cases 

 is that of the larvcB either mature or approaching maturity. 



Figs. 1, 2, and 8 were drawn by Miss Cundell ; figs. 9 to 17 by 

 Mr. J. T. Murray ; the remainder by the writer. 



Fig. 1. — The larvae of Hemerophila abruptaria, reared among 

 green shoots and leaves of lilac (food-plant), upon which they are 

 shown in the figiu-e. 



Fig. 2. — The larvae of the same species fed on the same food, 

 with which a number of very dark twigs were intermixed. The 

 larvae are seen at rest on a branch of Quercus cerris. The attitude 

 of the resting larvae in this and fig. 1 is not quite natm^al, A 

 cocoon is shown on the right side of the base of the branch. Its 

 strong resemblance to the bark is produced by the number of small 

 fragments gnawed off and woven into it. 



Fig. 3. — A dark larva of Rumia cratcegata brought up among 

 dark twigs. A bluish "bloom" is seen upon it. 



Fig. 4. — Another dark larva of the same species brought up 

 under the same conditions. The "bloom" covers more of the 

 surface, and a small patch of green colour is seen behind the dorsal 

 humps. 



Fig. 5. — A very black larva without "bloom," brought up under 

 the same conditions. 



Fig. 6. — A brownish green larva of the same species, fed on the 

 same food-plant (hawthorn), but brought up among green shoots 

 and leaves. A bluish "bloom" is present. 



Fig. 7. — A light brown larva with green marks and patches, 

 brought up under the same conditions as the last described. 



The larvae represented in figs. 3 — 7 were bred from eggs laid by 

 one moth, and were fed on the same food. It is interesting to note 

 considerable individual differences among the dark and light forms 

 respectively. The stimulus being the same, the reaction differs 

 somewhat according to individual predisposition. 



Fig. 8. — A large mature green larva of Amphidasis betularia 

 (one of the results of the 1889 experiments), shown in a very 

 characteristic attitude on a green twig of Populus nigra. The 

 brownish shade over the dorsal area is more or less present in the 

 majority of gi'een larvae of this species. 



Fig. 9. — This and all remaining figm'es represent the results of 

 (he 1892 experiments, 



