241 



CHAPTER VIII. 



FISH. 



Although we here pass into the sub-kingdom of animals 

 the intelligence of which immeasurably surpasses that of the 

 other sub-kingdoms, it is remarkable that these lowest 

 representatives of the higher group are psychologically in- 

 ferior to some of the higher members of the lower groups. 

 Neither in its instincts nor in general intelligence can 

 any fish be compared with an ant or a bee — a fact which 

 shows how slightly a psychological classification of animals 

 depends upon zoological affinity, or even morphological or- 

 ganisation. For although a highly competent authority, 

 namely Van Baer, has said that a bee is as highly organised 

 an animal as a fish, though on a different type,^ no one would 

 be found to assert that an ant or a bee is so much more 

 highly organised than a fish as its higher intelligence 

 would require, supposing degrees of intelligence to stand 

 in necessary relation to degree of organic development. 

 And this consideration is not materially altered if, instead 

 of regarding the whole organism, we look to the nervous 

 system alone. There is no doubt that the cerebral hemi- 

 spheres of a fish, although small as compared with these 

 organs in the higher Vertebrata, are, bulk for bulk, 

 enormous as compared with the oesophageal ganglia or 

 ' brain ' of an insect ; while the disproportion becomes 

 still greater if the cerebral hemispheres of a fish are com- 

 pared with their supposed analogues in the brain of an 

 ant, viz., the pedunculated and convoluted lobes which 

 surmount the cephalic ganglion. But here the relative 

 smallness of the ant as a whole must be taken into con- 



1 PUl. Frags., translated by Huxley, Tmjlor'8 Mag., 1853, p. 196. 



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