Cuap. XI.J MUSICAL SEA-SOUNDS. 385 
exist, not only in fishes', 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?, 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. 
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.* 
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 Acassiz, Comparative Physio- 
logy, sec. ii. 158. 
? It consists of two round vesicles 
containing fluid, and crystalline or 
elliptical calcareous particles or 
otolites, remarkable for their oscil- 
latory action in the living or re- 
cently killed animal. Owen’s 
Lectures on the Comparative Ana- 
tomy and Physiology of the Inver- 
tebrate Animals, 1855, p. 511-552. 
’ Tam informed that Professor 
Mixer read a paper on “ Musical 
fishes” before the Academy of Ber- 
lin, in 1856. It will arebatly be 
found in the volume of Mixrmr’s 
Archiv. fiir Physiologie for that 
year; but I have not had an op- 
portunity of reading it, 
‘ Edinburgh Philosophical Journ., 
vol. xiv. p. 188. See also the Ap- 
pendix to this chapter. 
ceo 
