THE LARGE BLUE 
247 
its second moult, while it was feeding on the Thyme blossoms. 
It was interesting to note that the larva paid no heed what¬ 
ever to the ant's running over and around it while it was 
feeding, but that the gland was extremely sensitive to the 
touch of an ant’s foot. When I touched the gland with 
the point of a very fine sable-hair brush, it would cause the 
gland to wince and contract, but by no means would it induce 
the exudation of the liquid, although directly an ant’s foot, 
or the claws of the foot, touched it, the bead of liquid was at 
once exuded. 
During their earlier stages, the larvae will readily devour 
each other, but after the third and last moult, all their canni¬ 
balistic habits entirely cease. 
The larva in full growth was unknown, and nothing was 
recorded of its existence after leaving the food plant in August. 
Therefore, after the success of discovering a pupa of M. arion 
in Cornwall on July 12th, 1905, in company with Mr. A. L. 
Rayward, I determined to visit the same ground in 1906 to 
endeavour to discover the full-grown larva. This we suc¬ 
ceeded in doing on June 3rd of that year. Then for the first 
time we had the satisfaction of gazing upon a natural object 
which had never before been seen by anyone. This specimen 
and three others we found in the top portion of an 
ant’s nest. They were just below the surface among the 
roots of small grass plants growing with the Thyme, and were 
in company with the ants and their larvae and pupae (vide 
The Entomologist , Vol. XXXIX, pp. 145-7, 1906). 
The third and final moult of the larva, which usually takes 
place in August, generally occupies three or four days, and 
after the process it rests for several hours. During this period 
of resting, the larva does not arouse any interest in the passing 
ants. After having rested for about six hours, it starts wan¬ 
dering aimlessly about, and being rather clumsy in its move¬ 
ments it often falls from the plant, and may even deliberately 
throw itself off. It wanders about on the ground, often 101 
hours, often making long pauses, waiting apparently for 
something, but it does not know what. The Wild Thyme 
has no further attraction for it. Finally, when a foraging ant 
comes across the larva, it at once takes the greatest interest 
in it. M. arion , however, does not seem at all pleased at the 
