SON(4 NOTES. 85 
but (]i(^ iiiosl caiH'Tul sliiilv made is thai hv riofi^ssoi- Kilcw" wIk* 
disliu*i;uisli(\s {\\vvo iinpoiiaiU iioUvs as cliaraclci'isl ic of diircrciit rea- 
sons or coiulilions of tlu* aci-ial life of (lie male iiix'cl. 
Tlio loudest and most cliarachM-isl ic iiolc, and llicoiic w hicli i.s \)v\-- 
lia})s most familiar to {\\c populai- mind, is the n()t(> docrilx'd l)\ 
Fitch as ■■ iH^])i'(\s(Mit(Mi l)\ \\\v let t (MS tsli-c-c-b^-lvlvl^-c-on , uticicd 
continuously and ])rolonu(Hl to a (|uart(M- or half miiuitc in Icn^tli, tlic 
niiddh^ not(^ doarcninuly shi-ill, loud, and piercing to the ear, and it> 
termination i^radually lo\v(M'ed until the sound expires." TIk* h'uuth 
of this note given by Fitch is ])robal)ly the niaxinnim tei'in and is 
unusual. Ordinarily it is nuich shorter, ranging from two (»i- thice 
to li\(' or ten or vwu twenty seconds. This note is the chaiacter- 
istic one of tlie height of the season, when great nund)ers 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 
iiitensity 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 
])ut^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 tunnel, or, when made by several individuals, more accu- 
rately to the croaking of certain frogs. 
A third, but less important, note is the clicking or intermittent 
chirping, consisting, of from 15 to 30 short, quick sounds, sometimes 
double, the whole lasting about five seconds, and resembling the 
shar]) clicking of the chimney swift or some of the field crickets. 
When disturbed and at the moment of taking fhght the insect is a])t 
to make a short cry^ or sharp chirp. 
All of these notes are said to occur in the small cassinii form, l)ut of 
higher pitch and less volume, but the clicking note seems to be the 
characteristic one of this variety. 
The strength and clearness of all the notes vary with th.e weather 
conditions. They are loudest when the air is dry and warm and 
glear, 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 continued 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 
" Science, Sepleniber 25, 1895. 
