1877.] The Use of the Antenne in Insects. 195 
am familiar in this country, the Promethea silk-worm moth is the 
one which in confinement will most readily accomplish the act of 
copulation. I have not yet found that a virgin pair on being put 
together did not unite the following afternoon. 
6. I took several virgin pairs of this species ( Callosamia Pro- 
methea), put each pair in a separate box, and let them remain to- 
gether until they died. Each male had been deprived of its an- 
tenne. I collected the eggs carefully ; without an exception they 
were unfertilized, sexual union not having taken place. 
Since making these experiments, it occurred to my mind that 
it might be objected that by cutting off the antenne of an insect 
the pain resulting from such a wound would sufficiently explain 
the failure of a congress of the sexes. I have many times ob- 
served the sexual union of insects with one or two legs wanting, 
with wings half broken, etc. So, last summer, in order to test 
the value of this objection, I procured a certain number of virgin 
Promethea just out of the cocoon, and mutilated the males in 
different ways, some by cutting off a piece of the wings, others 
by the removal of a leg. These mutilated males were put with 
the virgin females, but notwithstanding their wounds union took 
place, and I raised young worms from the eggs laid by the fe- 
males, 
T. One afternoon I was sitting upon a rock under the shade of 
a tree, when my attention was attracted to a procession of a 
large species of ant, going from the nest to a considerable dis- 
tance to gather, I think, some article of food. I contemplated in 
silence for some time the efforts of these industrious little labor- 
ers, when an idea crossed my mind that I had an opportunity to 
make one more experiment upon the use of the antenne. I 
caught two or three of them, and with a small pair of scissors cut 
off the antennæ, and then I let them go free by the side of their 
busy comrades. But it was of no use ; they did not seem to rec- 
ognize their brothers, and did not follow the same path, but 
Would trace a circle and turn about in every direction as if to 
find the route they were following before, not seeing that they 
had crossed it hundreds of times, and that their friends were fol- 
lowing that same route ; their eyesight was not sufficient to ena- 
ble them to discover their way. After observing them for more 
than an hour, I found that they had not gone out of this circle 
when I left them. 
From the second experiment I infer that when deprived of 
Sight, insects fly with less boldness and accuracy, but they do not 
