THE EXTERNAL ANATOMY OF INSECTS 93 



The following examples taken from his paper on "The Songs of 

 our Grasshoppers and Crickets" will serve to illustrate this method 

 of notation. 



The chirp of Gryllotalpa borealis (Fig. 103) "is a guttural^ sort of 

 sound, like gru or greeu, repeated in a trill indefinitely, but seldom 



Fig. 103. The chirp of Gryllotalpa borealis (From Scudder). 



for more than two or three minutes, and often for less time. It is 

 pitched at two octaves above middle C." 



xr! *r! xr! XT! 



Fig. 104. The chirp of the katydid (From Scudder). 



The note of the true katydid, Cyrtophyllus concavus, (Fig. 104) 

 "which sounds like xr, has a shocking lack of melody; the poets who 

 have sung its praises must have heard it at a distance that lends 

 enchantment." "They ordinarily call 'Katy' or say 'She did' rather 

 than 'Katy did' ; that is they rasp their fore wings twice more fre- 

 quently than thrice." Mr. Scudder in his account of this song fails 

 to indicate its pitch. 



h. INSECT CHORUSES 



Most insect singers are soloists, singing without reference to other 

 singers or in rivalry with them. But. there are a few species the 

 members of which sing in unison with others of their kind that are 

 near them. The most familiar sound of autumn evenings in rural 

 places in this country is a chorus of the snowy tree cricket, CEcanthus 

 niveus. Very many individuals of this species, in fact all that are 

 chirping in any locality, chirp in unison. Early in the evening, when 

 the chirping first begins, there may be a lack of unanimity in keeping 

 time ; but this lasts only for a short period, soon all chirp in unison, 

 and the monotonous beat of their call is kept up uninterrupted 

 throughout the night. Individual singers will stop to rest, but when 

 they start again they keep time with those that have continued the 

 chorus. 



Other instances of insect choruses have been recorded. Sharp 

 ('99, 156) quotes accounts of two produced by ants; one of these is 

 given on an earlier page (p. 80). 



