INSECT INSTRUMENTALISTS — ALLAED 573 



strokes follow one another at a rate of from 125 even up to 300 per 

 minute. Owing to the microscopic character of the musical struc- 

 tures and the brief period of the note produced by the single forward 

 movement of the scraper over such a microscopic file vein, the notes 

 ti are strikingly smooth and tinkling, in reality little more than 

 points of sound. Naturally there is no quaver or tremolo in the 

 notes, as in the case of those chirping crickets where the chirp is 

 made up of several forward strokes of the scraper. This is a most 

 remarkable technique and marks the extreme of slow speed in the 

 production of sound by the crickets. So far as my experience goes 

 it is the accomplishment of Anaxipha exigiia alone. 



In the katydid family Tettigoniidae., at least, one cone-headed katy- 

 did, N eoconocephalus ensiger^ of the North, produces in a similar 

 manner each tsip of its continuous untiring song tsip-tsip-tsip-tsip- 

 tsip-tsip-tsip with a single forward stroke of the scraper upon the 

 file vein, at the relatively slow rate of about one hundred and fifty to 

 two hundred times per minute. On the other hand, the big cone- 

 headed katydid, Neoconoce'phaJus exiliscanorus, like the snowy tree 

 cricket, for each quavering rasp — dzeet — employs several wing 

 strokes. 



STRIKING THE INDIVIDUAL TEETH OF THE FILE VEIN TO PRODUCE 



SOUND 



There is yet another possibility in this slowing down in the process 

 of producing sounds by drawing a scraper over the teeth of the file 

 vein. It involves a movement so slow and nicely controlled that the 

 teeth themselves are struck separately to produce a leisurely series of 

 30 to 40 sounds or clicks. Remarkable as it may seem a single katy- 

 did, the larger angular-winged kat^^did, Microcenbiim rho?nhifoIium, 

 has adopted this procedure, and I know of no other katydid that has 

 done so. A remarkable feature of this method of stridulation is the 

 loudness of the notes struck off by tapping these almost microscopic 

 teeth, but life is eternally doing many things to surprise us. It is, 

 perhaps, not more remarkable than to see the thin, transparent wings 

 of a snowy tree cricket throwing off surprising volumes of sound 

 from far smaller teeth, so that its chirp can be- heard hundreds of feet 

 away. None of the crickets have proceeded in this direction any 

 further than to make their notes with a single stroke over the entire 

 file vein, as the tiny Anaxipha exigua has done. Nevertheless, this 

 is a potentiality for the crickets as truly as for the katydids. It is 

 quite possible that a more thorough study of the thousands of musical 

 insects of the world will yet reveal this specialized technique among 

 some of the crickets. It is a marvelous accomplishment, and should 

 tonality or musical pitch still obtain one would expect to find a purity 

 of tone struck from each slender tooth as lively and as vibrant as any 



