THE SONG OF THE CICADA. 
367 
brought out under the name of “ Cri-cri.” In order to make 
the model act, all that is necessary is to hold the frame of the 
instrument in the left hand, while with the thumb and fore- 
finger of the right the free portion of the two steel springs is 
alternately and rapidly brought together and again let go ; 
and, as the depression in the two plates thus becomes by turns 
convex and concave, a stridulation is produced which is a fair 
imitation of the sound of the Cicada. The drums are imitated 
by the depression in the steel springs, while the motor muscles 
of the former are represented by those of the left hand. 
The musical apparatus of the male Cicada is classed by Mr. 
Darwin (“Descent of Man,” vol. i., p. 350) as one of the 
“ secondary sexual characters ” among insects. Apropos of 
this he quotes (op. cit.p. 351) from a journal of Dr. Hartman, 
the following about C. septemdecim in the United States : — “ The 
drums are now heard in all directions. This I believe to be the 
marital summons from the males. Standing in thick chestnut 
sprouts about as high as my head, where hundreds were around 
me, I observed the females coming around the drumming males.” 
Fritz Muller, moreover, wrote to Mr. Darwin from S. Brazil 
that he has often listened to a musical contest between two or 
three males, who had a particularly loud voice, and were perched 
at a considerable distance from each other. “ As soon as the 
first had finished his song, a second immediately began ; and 
after he had concluded, another began, and so on.” If there 
is so much rivalry between^the males, it is probable that the 
females not only discover them by the sounds emitted, but that, 
like female birds, they are excited or allured by the male with 
the most attractive voice. 
EXPLANATION OF PLATE X. 
In all the Figures the corresponding parts are indicated "by the same let- 
ters. The body of the Cicada is supposed to be placed vertically, the head 
being above. The three first figures are taken from the plate (PI. XI.) 
illustrating M. Carlet’s article in the Annales des Sciences Naturelles. 
Fig. 1 . The interior of the musical apparatus, seen from above ; a vertical 
transverse section having been made across the body of the 
insect. The muscle of the drum, the folded membrane, and 
the operculum , have been removed on the left side. On the 
right is seen the muscle of the drum, its small triangular 
tendon, and its semi-annular membrane, also the tensor muscle 
of the folded membrane, and the lower part of the sterno- 
entogastric muscle in section. The deep aspect of the drum, 
