LYCiENA II., III. 
11 
ined carefully your larvae, and some in alcoliol of Lycaena Argus and Corydon. 
All have the organs alike. On the penultimate segment you find outside and 
behind the stigmata two large white spots, each one of which evaginates a white 
membranous tube, just like the finger of a glove, the top of which is not entirely 
drawn out. I have seen the tube frequently, and if I blow a little the tube is m- 
vaginated instantly. On the antepenultimate se o men t is a lai n e 
opening behind and between the stigmata near the apical border. It looks like a 
closed mouth with its lips, but I have not seen anything protruding from it. 
But in an alcoholic larva of Argus I saw an ovoid evagination." Dr. Hagen also 
referred me to a paper by M. Guenee, Ann. feoc. Ent. de France, sei. 4, A ol. A II., 
1867, pp. 696-7, and Plate 13, in which are described and figured similar organs 
in Lycsena Bcetica. This author relates that while observing the larva of Boetica 
he noticed two openings altogether like those of the stigmata, and as he turned 
the caterpillar about it suddenly made spring out of these holes a peculiar body, 
which he cannot compare to anything better than to the tentacles which certain 
polypi put forth at will. And describing these, he goes on to say: " At the 
summit of the 10th segment” (the lltli, counting the head as one), "is found 
another opening placed transversely and surrounded by a raised pad. Fiom the 
middle of this opening comes forth, at the will of the caterpillar, a soit of trans¬ 
parent, hemispherical vesicle, which gives escape to a fluid sufficiently abundant 
to form a good-sized drop, which reproduces itself when it is absorbed. The cat¬ 
erpillar only secretes this fluid when it is disturbed. . . . As to the end vhicli 
nature proposes by this exceptional structure, it is not easy to divine it.” 
In 1878,1 was able to make more satisfactory observations, beginning with the 
larva? of Psmdargiolus , on Rattle-weed, and experimented in various ways on 
both larvae and ants. In each subsequent year I have continued the observa¬ 
tions, and 'in 1883 especially I lost no opportunity. The ants, when discovered 
on a stem, are almost invariably on or near the larvae. They run over the body, 
caressing incessantly with the antennae, and undoubtedly with the object of peibiiad- 
ing the larva to emit the fluid from 11. Much of the caressing is done about the 
anterior segments, and while the ants are so employed, or rather while they are 
absent from the last segments, the tubes of 12 are almost constantly exposed to 
full extent, and so remain, without retracting, until the ants come tumbling along 
in great excitement, and put either foot or antenna directly upon oi clo>c b\ the 
tubes, when these are instantly withdrawn. The ants pay no heed to the tubes, 
so far as touching them with intention, but at once turn to 11, caress the back of 
that segment, put their mouths to the orifice there, and show every sign ot eager 
expectancy. By holding a hand-glass on 11, a movement will speedily be appar¬ 
ent, and there will protrude a dark green mammilloid membrane, from the top 
