Chap. XI.] MUSICAL SEA-SOUNDS. 385 



exist, not only in fishes 1 , but in mollusca. In the oyster 

 the presence of an acoustic apparatus of the simplest 

 possible construction has been established by the disco- 

 veries of Siebold 2 , and from our knowledge of the reci- 

 procal relations existing between the faculties of hearing 

 and of producing sounds, the ascertained existence of 

 the one affords legitimate grounds for inferring the co- 

 existence of the other in animals of the same class. 3 



Besides, it has been clearly established, that one at 

 least of the gasteropoda is furnished with the power of 

 producing sounds. Dr. Grant, in 1826, communicated to 

 the Edinburgh Philosophical Society the fact, that on 

 placing some specimens of the Tritonia arborescens in 

 a glass vessel filled with sea water, his attention was 

 attracted by a noise which he ascertained to proceed 

 from these mollusca. It resembled the " clink " of a 

 steel wire on the side of the jar, one stroke only being 

 given at a time, and repeated at short intervals. 4 



The affinity of structure between the Tritonia and 

 the mollusca inhabiting the shells brought to me at 

 Batticaloa, might justify the belief of the natives of 

 Ceylon, that the latter are the authors of the sounds I 

 heard; and the description of those emitted by the 

 former as given by Dr. Grant, so nearly resemble them, 

 that I have always regretted my inability, on the occa- 



1 Agassiz, Comparative Physio- 3 I am informed that Professor 

 logy, sec. ii. 158. Muixer read a paper on ''Musical 



2 It consists of two round vesicles fishes" before the Academy of 33er- 

 containing fluid, and crystalline or lin, in 1856. It will probably be 

 elliptical calcareous particles or found in the volume of Muller's 

 otolites, remarkable for their oscil- Archiv. fur Physiologie for that 

 latory action in the living or re- year; but I have not had an op- 

 cently killed animal. Owen's portunity of reading it. 

 Lectures on the Comparative Ana- 4 Edinburgh PhilosophicaUourn., 

 tomy and Physiology of the Inver- vol. xiv. p. 188. See also the Ap- 

 tebrate Animals, 1855, p. 511-552. pendix to this chapter. 



C C 



