PHOF. LIPARI ON THE SOUNDING ORGANS. Ivii 



cause the stridor. He says " Les deux petits miroirs 

 comine deux tambours ne rendoient pas les sons," for 

 "les baguettes," are wanting, besides which the films 

 are too slack to yield sound. Again, " Pendant que je 

 tirallois doucement (le tamboure) avec un epingle, 

 pendant que je le faisois un peu sortir de sa place, 

 pour I'y laisser retourner, ensuite il m'arriva de faire 

 chanter un cigale morte depuis plusieurs mois. Le 

 chant, comme 1 'imagine, ne fut pas fort." 



The rapid quivering of the Cicada's drum, though 

 wonderful, is not really so great as that performed by 

 the gnat whilst vibrating its wing and shrilly piping 

 in its flight. 



In a February number of ' Nature ' * a diagram- 

 matic drawing, by Mr. C. Lloyd Morgan, may be seen 

 of the sounding organs of a South-African Cicada, 

 which drawing virtually agrees with Prof. Lipari's 

 account of the apparatus. He further makes the inte- 

 resting remark, that under the stimulus of a weak 

 current of electricity, the singing noise can be sustained 

 for some minutes after the apparent death of the insect. 



Mr. C. Middlemiss also states that a Himalayan 

 species likewise produces its screech by a rapid 

 wrinkling of its parchment-like drum. 



Thus it is shown that the chirp of the Cicada differs 

 from that of the Grasshopper, and that nothing acting 

 as a plectrum is concerned in the production of the 

 sound. Special muscles act on a tense corrugated 

 membrane, which is rapidly pulled downwards, and as 

 often released. A similar creaking noise may be made 

 by alternately pulling and releasing a string fixed to 

 the centre of a tense paper disc, glued on a metal 

 ring. 



Figures illustrating the various parts from Prof. 

 Lipori and Mr. C. L. Morgan will be found reproduced 

 on Plate B of this Monograph. 



■■' ' Nature,' Feb. 18, 188G, p. 368 ; also " Notes on the Singerjie, the 

 well-known Cicada of the Cape of Good Hope, Platijideura cajjensis," 

 Proc. S. African Phil. Soc. 1879—1880, pt. iii. p. 101. 



