LYC^NA II., III. 
15 
itself to the utmost to reach its prey. The sting was just about to strike the 
extreme end of the larva, when the ant made a dash at the fly, which flew 
away, and so long as I stood there, at least five minutes, did not return. 
The larva had been quiet all this time, its head buried in a flower bud, but 
the moment the ant rushed and the fly fled it seemed to become aware of the 
danger, and thrashed about the end of its body in great alarm. The ant 
saved the larva, and it is certain that Ichneumons would in no case get an 
opportunity to sting so long as such a vigilant guard was about. It seems to 
me that the advantage is mutual between the larvae and ants, and that the 
former know their protectors, and take satisfaction in rewarding them. This 
was the only occasion which has fallen under my observation in which the actual 
attempt to sting was defeated; but on 16th June, 1881, I saw several larvae and 
several ants on a stem of Rattle-weed, about which one of these flies was hover¬ 
ing. It came very near to one larva, but an ant, not standing upon the latter, 
ran at the fly, which then departed. On 20th June, 1879, I saw another fly 
creeping along a stem on which was a half-grown larva, but no ant. The fly 
moved up, put one leg on the larva, rested an instant, turned round, and when 
I thought it was about to give the fatal thrust it hesitated, and after standing 
quiet more than two minutes flew away. I concluded that either the larva was 
too young for the purpose of the fly, or that the latter discovered that it had 
already been parasitized. I have introduced house flies to larvae in tubes, and 
there was no alarm, nor was any notice taken, though the flies buzzed about and 
even stood on the larvae. 
Whether all other species of Lycaena are supplied With the special organs above 
described I cannot say. Very little observation seems to have been made on this 
point. The books have rarely spoken of either the organs, or of ants attending 
the larvae, and in most cases the observations seem to have been isolated, and the 
object for which the ants attended the larvae undiscovered; or if the organs were 
observed, the connection with the ants was not. In Newman’s British Butter¬ 
flies, Lond. 1871, p. 125, I find this sentence quoted from Prof. Zeller: “ I could 
not perceive that these caterpillars (L. Meclon) had a cone capable of being pro¬ 
truded, like that which we find in L. Cory don, and which the ants are so fond of 
licking.” Guenee, as has been seen, discovered the tubes and the organ on 11, 
and saw the fluid exude therefrom, but could not conjecture its object. 
Dr. Hagen called my attention to the following mention in Stett. Ent. Zeit., 
XXVI. p. 115, 1845 : “ Mr. C. Plotz says that he found caterpillars of L. Argus 
on Calluna vulgaris. Was puzzled at seeing that every caterpillar had an ant 
standing on its back, and saw about forty larv<© near ant hills, the ants always on 
the larvae, standing or walking, and apparently the caterpillars were in no way 
