LOW INTELLIGENCE OP REPTILES AND FISHES. 387 



by education, and being performed under the direction of 

 an Intelligence much higher than the boasted reasoning 

 power of Man. 



485. In the classes of EEPTILES and FISHES, the manifesta- 

 tions of Intelligence are so slight as to be scarcely distin- 

 guishable. We find them capable of such an amount of 

 education as enables them to recognise individuals from whom 

 they have been accustomed to receive food ; but they seem to 

 have very little further power of profiting by experience ; and 

 we do not find that individuals ever shape-out for themselves 

 a new course which can be regarded as purely rational. This 

 very low grade of Intelligence obviously corresponds with 

 the very rudimentary development of the Cerebrum in these 

 classes ( 453, 454). 



The contrast between Instinct and Intelligence will be more 

 fully displayed in a future Chapter ; in which also a general 

 account will be given of the Mental Operations to which the 

 Cerebrum of Man is subservient. 



CHAPTEE XL 



ON SENSATION, AND THE ORGANS OF THE SENSES. 



486. ALL save the very lowest kinds of Animals possess, 

 there is good reason to believe, a consciousness of their own 

 existence, first derived from & feeling of some of the changes 

 taking place within themselves; and also a greater or less 

 amount of sensibility to the condition of external things. 

 How far any such endowment can be possessed by creatures 

 which are destitute of a nervous system, and which are little 

 else than particles of animated jelly, may be questioned. But 

 there can be no reasonable doubt that where a nervous 

 system exists, whatever consciousness any Animal may pos- 

 sess of that which is taking place within or around itself, is 

 all derived from impressions made upon the extremities of 

 certain of its nervous fibres ; which, being conveyed by them 

 to the central sensorium, are there felt ( 430). Of the mode 

 in which the impression, hitherto a change of a material cha- 

 racter, is there made to act upon the mind, we are absolutely 

 ignorant ; we only know the fact. Hence, although we com- 



c c 2 



