320 Dr. T. A. Chapman on the Evolution of the 



not. It is also the case that the larvae leave these tents 

 to feed, and return to hide themselves in the ground amongst 

 the debris covering the ants' nest — a habit that obtains 

 even if the soil beneath the plant has no ants' nest in it, 

 as they nevertheless hide in the soil by day if they can get 

 under it, or if they cannot penetrate it, then amongst the 

 plant stems close to the ground. It is therefore possible 

 to say that the larvae protect themselves in this way during 

 moulting. 



I feel interested in all this as mere speculation, for others 

 I may submit that its value consists in showing that 

 whilst we have solved some important and interesting 

 problems in the life-history of L. arion, we have opened 

 the view of others that will require probably even more 

 careful work and prolonged observation and experiment to 

 solve them. 



(October 2.) Since writing the above, I have received 

 from Mr. Harold Powell some material bearing on the life- 

 history of L. alcon. The mature larva described as green, 

 etc., lives, according to report, on Gentiana pneumonanthe 

 in spring, and I have already referred to its first stage. 

 Mr. Powell found the food-plant bearing many eggs ; when 

 he came to examine them, however, he discovered the 

 curious circumstance that they were all empty, the larva 

 escaping from the lower aspect of the egg, leaving it 

 looking intact and apparently full — a circumstance that 

 only occurs in any Lycaenine, whose eggs I have had, as a 

 really rare accident. The young larvae, however, had not 

 bored directly into the plant tissues beneath, but had 

 apparently entered the flowers. 



Mr. Harold Powell, however, sent me heads of Gentiana 

 pneumonanthe (Sept. 22, 1916) in the flowers of which 

 larvae of L. alcon had fed ; unfortunately they had practi- 

 cally all left the flowers for some unknown place (for hiber- 

 nation). An examination of the flowers showed, however, 

 abundance of eggshells, generally laid on the calyx, from 

 which the larvae had escaped from the under surface, 

 entering the still unopened flower. A close search was 

 rewarded by cast heads of the first instar, and one dead 

 larva in this instar. Skins cast at the second moult were 

 abundant, *'. e. there were usually several, often four or 

 five, in one flower. One dead larva was found, just about 

 to moult for the third time ; inside the skin was the rather 

 immature fourth-instar larva. 



