CARr. 13 



which they are adapted predominates over understanding or 

 reflection; yet when proportionate magnitude is added to pecu- 

 liarity of structure, the former must be regarded as an important 

 element in the display of the faculty of understanding. There 

 is a peculiarity in the nerves, especially those of the senses, as 

 of sight, taste, and hearing, in that neither of them can be 

 taught to perform the functions of another; and there is pre- 

 sumptive proof that this remark may be extended to essential 

 portions of the brain itself; and that it is in this the conscious 

 identity of every creature resides, or from which it derives its 

 existence, which therefore intrinsically constitutes the true dis- 

 tinction of species. If there be a time when the nature of any 

 creature appears to be substantially changed, so that the fearful 

 becomes bold, or the contrary, when hunger suspends the 

 indulgence of its appetite, and the wanderer confines itself to 

 one solitary spot, it is when by the temporary preponderance 

 of one specific nervous energy the action of the others appears 

 superseded; and this most frequently occurs at the season of 

 procreation; at which time Pennant informs us that the cautious 

 and cunning Carp becomes so simple as to suffer itself to be 

 tickled, handled, and caught by any one who will attempt to 

 do it. 



But the outward senses of this fish, as well as its inward 

 consciousness, are acutely alive to sensation; of which one set 

 of instruments is the barbels at the mouth, which in some 

 degree corresponds to what is also a character of the Cod family. 

 The pad also in the roof of the mouth is elastic and highly 

 sensitive, being furnished with a large number of nerves, which 

 are derived from the eighth pair as they arise from the brain, 

 and are peculiarly fitted to receive these impressions. That these 

 fishes are brought together by sounds is a proof of the quickness 

 of their hearing as well as of their knowledge of the object for 

 which they are made to assemble; in which particular again 

 they resemble the Mullets; and by dissection it is found that 

 their organs of hearing are not a little complex; with some 

 reference again to the air-bladder, which, unlike what is found 

 in most other fishes, is double in the Carp, as well as in the 

 Tench and some others of this family; and this doubling is 

 formed by means of a constriction towards its upper portion; 

 from the second division of which proceeds a tube, which 



