CARNIVOROUS BUTTERFLIES CLARK 483 



the lower aurface Avas the posterior portion of the gut full of 

 a dark material. It measured 3 mm. in length and over 0.5 mm. 

 in thickness, and was rather hard and solid. Farther forward in 

 the gut there were also portions of contents, rather soft and easily 

 pressed flat on a slide. 



The posterior portion of the dark mass was rather shorter and 

 more slender than the forward portion. It showed a quantity of 

 granular material in layers of darker and lighter appearance. The 

 forward portion seemed to consist of a mass of minute hairs of 

 fairly uniform size and structure. The less dense material found 

 farther forw^ard in the gut showed a number of identical hairs, and 

 also some small triangular chitinous bodies very like mandibles of 

 some insect. 



On comparison Doctor Chapman found that the hairs in the 

 arion caterpillar agreed absolutely with the hairs of the fully grown 

 larvae of the ant Myrniica scdhrinodis^ while the chitinous triangles 

 agreed exactly with the mandibles of the same larvae. Nothing of a 

 vegetable nature was found amongst these contents, and it could not 

 be doubted that the caterpillar had eaten many ant larvae, and 

 nothing else for a long time. 



Doctor Chapman remarked that it seems highl}?^ probable that the 

 caterpillar of Lycama avion in its last stage behaves as do the larvae 

 of many bees and wasps, various parasites, and other insects that 

 live on material that is practically all digestible and contains very 

 little effete matter; that is, it does not, imtil it has completed its 

 growth, evacuate any of the contents of the gut, but allows all the 

 undigested material and effete matter to accumulate in the rectum 

 during the Avhole period of growth, to be ejected when the period for 

 pupation approaches. Such a procedure is not known in the case of 

 any other butterfly. 



The posterior and therefore earlier portion of the waste matter 

 gave no indication of what food it represents, though the later por- 

 tion represents many ant larvae all apparently in their last stage. 



Doctor Chapman raises the question whether the first portion 

 represents eggs or young larvae of the ants that were more thor- 

 oughly digestible and so left no recognizable detritus, or whether the 

 earlier diet was a vegetable one. 



At a meeting of the Entomological Society of London, held on 

 November 7, 1917, Capt. E. B. Purefoy exhibited a short series of 

 LycfEna avion which he had bred from the &gg. After the third 

 molt they had been carried into the nests of Mynnica Imvinodis. 



At the same time Mr. Horace Donisthorpe corroborated an ob- 

 servation of Doctor Chapman's that the ants, on being disturbed, 

 carry off the larvae of lycaenids, beetles, etc., before removing their 

 own young. 



