SEVENTEEN-YEAR LOCUST: 1ST MUSICAL APPARATUS. 175 



expand, all the organs have become fully developed, and the insect has 

 attained its perfect stage, as shown at c. If food is needed, it punc- 

 tures the twigs with its beak, shown at a, in Fig. 44, and feeds upon the 

 sap. After two or three weeks of a merry life, if we may judge from 

 the almost ceaseless music with which the days are made vocal, the im- 

 portant work of oviposition is commenced and soon completed. An- 

 other month, and the brood, of so many years' gradual development, 

 has become extinct. 



Its Music and Musical Apparatus. 



Dr. Fitch has referred to " the discordant din of the Cicada's shrill 

 song." In endeavoring to convey an idea of the peculiar note, he says 

 — "it is repeated at short intervals, and may be represented by the.let- 

 ters tsh-e-e-E-E-E-E-e-e-ou, uttered continuously, and prolonged to a 

 quarter or a half minute in length, the middle of the note being deafen- 

 ingly shrill, loud and piercing to the ear, and its termination gradually 

 lowered till the sound expires " (Ls-^ Rept. Ins. New York, p. 42). 



They appear to be capable of producing different sounds, for Prof. 

 Riley states that " when disturbed the noise they make mimics a nest of 

 young snakes or young birds under similar circumstances — a sort of a 

 scream. They can also produce a chirp somewhat like that of a cricket " 

 {\st Rep. Ins. Mo., p. 24). 



Dr. Burnett has made the musical apparatus of the Cicada the sub- 

 ject of careful study. He found it to be wholly integumental in its na- 

 ture, and not presenting any relation either by structure or analogy to 

 the respiratory system. The drum is situated in each side between the 

 thorax and abdomen, having its head, which is of the size of a marrow- 

 fat pea, just under the point where the wings are attached to the body. 

 It is a tense, dry, crisp membrane, crossed by cords or bars, produced 

 by a thickening of the membrane, which meet on one side at the point 

 of attachment of the muscles, which, by their contraction, keep it 

 stretched. The sound is produced by a series of rapid undulations, 

 running from the contracting muscles across the drum. The upper part 

 of the abdomen serves as a sounding board, for with a portion removed, 

 the sound is diminished in volume. A dry condition seems to be essen- 

 tial to the perfect action of the drum, as when it is moistened, or on 

 wet days, the sound is very much diminished. The drumming is 

 heard for four or five hours during the heat of the day, principally be- 

 tween the hours of twelve and two. In the female, there is no drum, 

 nor any trace of the muscular apparatus belonging to it (Proc. Bost. 

 Soc. Na(.Hist.,\y, 185 1, p. 72). 



