58 THE PERIODICAL CICADA. 
given by Fitch is probably the maximum term and is unusual. Ordi- 
narily it is much shorter, ranging from two or three to five or ten or 
even twenty seconds. This note is the characteristic one of the height 
of the season, when great numbers of males are singing together, and 
is rarely made by solitary individuals or when there are only a few 
together. Some instinct also seems to prompt the singing in unison, 
and as it rises at such moments the intensity and volume of sound has 
a startling and weird effect. 
The second important note is what is ordinarily known as the " Pha- 
r-r-r-aoh " note, and is made early in the season, or when the males are 
few in number and recently emerged. The termination of this note is 
notable even more than the last for its peculiar mournful cadence and 
lowering of pitch, which is very characteristic. It lasts but two or 
three seconds. It has been compared, rather fancifully, I think, by 
Professor Riley to the whistling of a train passing through a short tun- 
nel, or, when made by several individuals, more accurately to the croak- 
ing of certain frogs. 
A third, but less important, note is the clicking or intermittent 
chirping, consisting of from fifteen to thirty short, quick sounds, some- 
times double, the whole lasting about five seconds, and resembling the 
sharp clicking of the chimney swallow or some of the field crickets. 
When disturbed and at the moment of taking flight the insect is apt 
to make a short cry or sharp chirp. 
All of these notes are similar in the small cassini form, but of higher 
pitch and less volume. As described by Dr. A. W. Taylor, it is 
" uttered without much change of tone, and, individually, is quite low 
as 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."' At the distance of a quarter of a mile 
it sounds " like the noise made by a swarm of bees passing through the 
air close at hand." 
The strength and clearness of all the notes vary with the weather 
conditions, and are loudest when the air is dry and warm and clear, or 
between the hours of 11 and 3 o'clock. On wet days, or when the air 
is unusually moist, the sound is much diminished, and heavy or contin- 
ued rains stop it for the time altogether. 
While it is almost universally true that the song of the Cicada is 
never heard between sunset and sunrise, they will, on very rare occa- 
sions, when disturbed, start up singing in concert in the middle of the 
night. Prof. A. D. Hopkins noted an instance or two of this kind in 
connection with the brood of Cicadas appearing in West Virginia in 
1897. He says: 
I was fortunate enough to bear the starting of one of these concerts on a clear, 
moonlight night in June. One male in an apple tree near the house suddenly called 
out as if disturbed or frightened. His neighbors in the same tree were thus appar- 
ently awakened. One started the familiar song note, which was at once taken up 
by numbers of other males, and, like the waves from a pebble dropped into still 
