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mentioned were uttered by both forms of the insect found here, and 
were so nearly alike that that uttered by either species could not be 
distinguished from similar sounds of its relative. I was somewhat sur- 
prised at this. The difference in the size of the insects and therewith 
in the size of the sound organs and of the controlling muscles should, 
I thought, indicate a difference in the sound produced. In the third 
distinct sound, that in which the males display their musical charms to 
the other sex, I found a difference which, in all the investigations I 
made, proved constant. The note of the varietal form is uttered with- 
out much change of tone and, individually, is quite low compared with 
that of the other form, but collectively the noise, when the observer is 
near, sounds like the rushing of a strong wind through trees of dense 
foliage. Ihave distinguished this sound at a distance of a quarter of 
a mile from the place of its origin, and at that distance it sounded like 
the noise made by a swarm of bees passing through the air close at 
hand. The sound made by the specific form is so peculiar as to at 
once attract attention. It is uttered in an uncertain quivering way, 
gradually rising, then falling and passing away as though ended by 
the exhaustion of the insect. This sound is well represented thus: 
Fe-e-e-ro-o-0. My friend, M. J. F. McKee, whose valued assistance I 
have had in preparing my notes on the Cicada, watzhed the action of this 
insect in giving utterance to this sound. He says: ‘*The male Cicada 
(C. septendecim) assumes a position on the upper side of a limb or on 
the body of a tree, always with the head upward, then it elevates the 
posterior enu of its body, at the same time appearing to inflate the 
abdomen. With the beginning of the sound the elevated portion of the 
body descends, the abdomen appears to contract until, when the parts 
reach their natural position, the notes cease. The insect then remains 
quiet for a period about equal to the length of the musical effort, when 
the performance is repeated. A noise may be produced from a freshly- 
killed male by taking hold of each end of the body with one’s fingers, 
and alternately expanding and contracting the abdomen, similar to the 
manner in which an accordion is played. The sounds thus produced 
are not similar to those produced by the insect itself, but in many par- 
ticulars there is a decided resemblance, and this, I think, demonstrates 
the manner in which the sounds are produced.” Evidently this is done 
by inflating the hollow abdomen with air, and then forcing the air 
against the corrugated surface of the insect’s drum-like membranes, 
when, by the vibration of these membranes as permitted by the power- 
ful muscles attached thereto, the noise is produced. I have not been 
enabled to make as satisfactory an examination of variety cassinti when 
uttering its sounds. They are evidently produced in a similar manner, 
but the motions occurring are different, a trembling of the posterior 
parts being all that I have discovered. 
Toward the latter part of their lives the Cicadas appear to be affected 
by a peculiar fungus growth. This is most common to the males, but 
