334 ORTHOPTERA OF NOVA SCOTIA. PIERS. 



21°, and on the night of 16-17th the thermometer went down 

 to 11° Far. Again in 1917, on 14th Oct., a sunny warm day 

 with a temperature of 56° Far., many crickets were heard, 

 but faintly. After various hard frosts, only a few were noted 

 on 29th Oct., although the sun was bright and the thermo- 

 meter at 47°. On the morning of 10th Nov. about an inch 

 and a half of snow was on the ground, but rapidly disappeared. 

 At noon on 11th Nov. I heard four crickets very faintly 

 shrilling, in different warm spots, during a three-mile walk 

 in the vicinity of Dutch Village, Halifax, and they proved 

 to be the last of the season. The day was a bright sunny 

 one, with a noontime temperature of only 31°, and the ground 

 muddy. On the 13th the thermometer was 24° at 9 a. m., 

 but sunny; and on the 15th the North West Arm was exten- 

 sively frozen about its head for the first time in the season. 

 This seems to show that the first hard frosts silence some of 

 them, but that a few survive as many as four ice-forming 

 frosts and frozen ground, and even evanescent snowfalls, 

 and that a still lower temperature or a fairly heavy fall 

 of snow which lasts for some time, finally causes the last 

 most favourably situated survivors to perish. 



The stridulation or shrilling note of the male is pro- 

 duced by the insect lifting the wing-covers about 45° above 

 the body, and then shuffling them very rapidly together 

 so as to vibrate the resonant organ at their base; thus pro- 

 ducing a trilling sound or tremolo, of a prolonged character,, 

 resembling the syllable ple-e-e-e, ple-e-e-e, ple-e-e-e, repeated 

 at rather short intervals or sometimes continued for several 

 seconds or even much longer. The sound has a peculiar 

 silvery timbre, and when myriads are shrilling all over the 

 fields at night, or on fine days in late autumn, when other 

 sounds are hushed and the air filled with the mystic charm 

 of the hour or season, it produces a peculiarly drowsy, cease- 

 less tremor, pulsation, or "shimmer" of sound which is. 

 very familiar and loved by all dwellers in the country.* It 



♦The continuous shrillinj? of this cricket reininJs ono s j.u.'.v.i.it of thu much louder 

 eraal trill of the American Toad when the latter is heard at a distance. 



