240 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
rivalry with his male companions. (See p. 234, Courtship of the 
Carolina Locust.) 
It is evident that in all of these methods the sound is produced 
by vibrations of the tegmina set up by the friction of the hind 
femora or impact of the wings. Sometimes the tegmina serve 
not only as sounding-boards but also by great concavity of shape 
form a resonating chamber, as in the Katydid (Pterophylla) . 
Stridulation while at rest may be readily witnessed in the field 
by using due caution in approach, and artificial light by night 
(of which the insects seem not to be afraid). They are sensitive 
to sudden movements and to the jar of footfalls, etc. If startled 
they may often be induced to recommence their song by the judi- 
cious use of a file and a quill or similar contrivance for imitating 
the sounds, approaching more closely after confidence has been 
restored. Or they may be watched at ease by capturing several 
of both sexes and keeping them in captivity with a supply of food 
and water. Single males perform well at times but the stimulus 
of companionship is usually productive of greater activity. 
A word of caution may not be amiss. When making observa- 
tions it is important to be absolutely sure of the identity of the 
insect musician (many errors are embalmed even in scientific 
literature), and to consider carefully the acoustic conditions of 
the spot where the sound is produced, — the song of the same 
Tree-cricket trilling high in air above one's head sounds faint 
and far away compared with its effect when given close to the 
ground and reflected toward the listener by an amphitheater of 
bushes. But it is an interesting pastime to follow in warm 
autumn days and the acquaintance of these little minstrels is 
well worth the effort necessary to secure it. 
The following papers on the subject of stridulation will be 
found helpful and suggestive, those by Scudder being the earliest 
in point of pubUcation, Allard's the latest. In addition, many 
notes will be found in the writings of Davis, Fulton, Rehn and 
Hebard, and others on particular groups or species. 
Allard, H. a. — "Musical Crickets and Locusts in north Georgia." Proc. 
Ent. Soc. Wash., vol. 12, p. 32-43 (1910). 
"Some New England Orthoptera observed in late October." Ent. News, 
vol. 21, p. 352-357 (1910). 
"Stridulations of some Katydids." Proc. Biol. Soc. Wash., vol. 23, p. 
3.5-40 (1910). 
