584 ANNUAL EEPORT SMITHSONIAN INSTITUTION, 19 2 8 



mechanism appears to be eternally within the grip of the temperature 

 level, comj)elling the same singers to slow down their notes from 135 

 chirps per minute at 70° F. to only G2 chirps per minute at 54° F. 

 So mechanized are these little insects in this respect that they have 

 been termed thermometer crickets, and formulae have been devised 

 to compute the air temperature from the rate of their chirping. The 

 niceties of the matter are, however, not so simple as this, for each 

 race has a physiological rate of its own, and this, as well as the indi- 

 vidual rate and still other factors, must be carefully worked out 

 before our crickets can begin to serve as very efficient audible ther- 

 mometers with tlieir rhythmic chirps. 



VARIATIONS IN THE NORMAL METHOD OF MUSICAL EXPRESSION 



Now and then, for some unexplainable reason, a cricket or katydid 

 develops an abnormal method of musical expression. Considering, 

 however, the countless numbers which one may hear in his lifetime 

 this is of very rare occurrence. A few years ago I came across a 

 big conehead, Neoconocephalus exilwcanonis^ chirping with the ton- 

 ality or pitch of a cricket — one of the most unusual departures that 

 has ever come to my notice. It has always been a myster}'^ to me 

 why the notes of all the katydids should so consistently lack musical 

 pitch as our ear defines it, while all the crickets " sing " with a 

 musical pitch or tonality. There is no more musical quality in the 

 squa-wtik of the true katydid, Pterophylla caTnellifolia, or the notes 

 of the Phaneropteras, Amblycor3^phas, Microcentrums, Orchelimums, 

 species of Neoconocephalus, Cojiocephalus, etc., than in the harsh 

 noise made by scraping a knife blade smartly across the teeth of a 

 comb. In spite of this mystery of the complete lack of tonality in 

 the notes of all the katydids, the katydid I have mentioned suddenly 

 became as a chirping cricket. Microscopic examinations of the file- 

 vein and scraper revealed nothing in the least abnormal, and I am 

 still profoundly nonplussed by this riddle of life as the musical 

 crickets and katydids have consistently made it. 



At another time I had placed in my bedroom a musical jumping 

 tree cricket, Orocharis saltator, that I might rest and dream to the 

 tune of its silvery, ringing chirps, and experience that sweet poetry 

 of companionship with the night sounds that leads almost to those 

 finer ecstacies of religious awe. Suddenly, in the night, I was 

 awakened from my sleep by an exceptional tone struck off by this 

 cricket; a loud clear scintillant note devoid of all the quaver which 

 usually attends its tremulous chirp. There were not many of these 

 notes, but I realize now, from later studies of the smooth, clear tones 

 of the little bush cricket, Anaxipha ex'igua^ that I had probably heard 

 the jumping tree cricket, in some unusual mood, strike off a few of 



