ORGANS OF TASTE AND SMELL. 167 



medium in which the animal exists ; it is an aquatic, 

 not an atmospheric ear, and is destined to receive so- 

 norous impressions in a dense medium. 



Various observers bear testimony as to the power 

 of smell which the cephalopods possess, and which is 

 asserted to be of considerable delicacy ; but no olfac- 

 tory apparatus has hitherto been demonstrated, though 

 Professor Owen regards as such certain laminated 

 membraneous appendages arranged longitudinally, which 

 he discovered at the entry of the mouth of the nautilus, 

 between the labial processes. These appendages are 

 abundantly supplied with nerves, which may be endowed 

 with the power of receiving impressions from odorous 

 particles contained in the water around them, and thus 

 serve to aid the animal in the choice of food. The 

 conditions of an olfactory apparatus for an aquatic 

 medium, must differ greatly from what are required 

 by organs destined for an aerial medium, and we may 

 expect a simplicity here parallel to that of the visual 

 organs ; and it is not improbable, that the lips of ordinary 

 cephalopods, or the tongue itself, may be gifted with 

 the sense in question, which is, in fact, but a kind of 

 taste — a taste of odorous particles of bodies diffused in 

 air or water. 



So far, then, a summary of the general structure of 



