EUTRICHA QtJERClFOLiA. 2l5 



Ceux en forme de pique s'etoient apparemment saisis de toute mon 

 attention. C'est dans la premiere enveloppe de la coque que j'ai 

 trouve les poils de la second espece, et leur couleur bleue, comme 

 celle des poils en fer de pique, me persuade qu'ils sont aussi places 

 dans les jonctions du premier anneau avec le second, et du second 

 avec le troisieme. Ces nouveaux poils sont des poils composes ; 

 ils sont des especes de poils en plume, ou en duvet, ou, plus 

 exactement, ils sont un paquet de poils, qui a tantot la forme d'un 

 petit balai, tantot celle d'une palme. Deux taches blanches de 

 figure triangulaire se sont remarquer sur la partie superieure du 

 second anneau. On appercoit de plus sur la partie superieure de 

 chaque anneau deux tubercules roux, charges chacun de poils de 

 mediocre grandeur. A la jonction des anneaux, il y a des especes 

 de cordons charnus, qui ne sont pas si distincts a, beaucoup pres sur 

 les anneaux des autres chenilles. La tete est bleuatre, et paroitroit 

 bleue, si elle n'etoit pas garnie de quantite de poils roux. La peau 

 de cette chenille merite d'etre observee a la loupe, elle ne paroit 

 qu'un rezeau. Sa tissure est semblable a celle d'une eponge fine" 

 (Afemoires, ii., pp. 287-289). 



Variation of larva. — There is considerable variation in the 

 larval coloration, Godart noticing more than three-quarters of a 

 century since that the colour difference was constant on different 

 foodplants, and Poulton has given us the results of certain experi- 

 ments which point distinctly to the variation being of value in 

 as much as they are capable of adjustment, within certain limits, to 

 the surroundings of the larva, and thus adding considerable value 

 to the protection afforded to the larva by its resemblance to its 

 surroundings. Bacot notes that in the first instar there is little colour 

 variation, but in the second the grey ground-colour varies, some larvae 

 having white marblings dorsally, which are usually strongest on the meso- 

 thorax, just behind the orange spots. Farren states that the larvae, in 

 nature, are well protected, for not only do they feed by night and rest by day, 

 low down on the stems of the foodplant, but, when at rest — on sallow, 

 whitethorn, blackthorn or buckthorn — so difficult are they to see that 

 a very general way of collecting them, is to feel down the stems for 

 them. They are very variable, and certainly seem to have the power 

 of adapting their colour to the stems of the particular bush on which 

 they feed, e.g., on blackthorn and buckthorn, the stems of which 

 are black and smooth, one finds mostly black larvae, whilst on sallow 

 and whitethorn, the stems of which are white or mottled grey, the 

 larvae match the colour ; they appear to follow this rule very 

 generally, though not, of course, without exception. Prout says 

 that on the lichen-covered blackthorns at Sandown some of 

 them are very prettily mottled like the lichen-marked form of the 

 larva of Gonodontis bidentata, etc. Carr notes that a black larva 

 on buckthorn at Wicken, June 18th, 1898, produced a male 

 on July 17th, whilst an ash-grey larva, on sallow, on June 20th, 

 produced a female on July 16th, 1898, but adds the suspicion 

 that the colour had to do with the environment and not with sex. 

 Merrin says that he has observed the larvae, in May, resting high 

 up on bramble branches, which their markings closely resemble. 

 Poulton, by surrounding living larvae during the early stages of 

 growth (the food being the same) with black twigs and lichen-covered 



