SUPERIORITY OF OUR SENSES. 357 



and animals. The ear of one man is utterly incapable of 

 appreciating those delicate intervals and harmonic combina- 

 tions which give to another exquisite delight. The bird, 



"Singing of summer in full-tbroated ease," 



is insensible to music, and probably distinguishes nothing in 

 speech except the loudness of the tone. And this fact may 

 lead us to question whether the general notion, so often 

 insisted on, of the superiority in the senses of animals over 

 those of man, is not a fallacy. It is quite true that a bird 

 sees distinctly at greater distances than a man ; but can it 

 see such delicate nuances of colour ? A dog perceives some 

 odours to which we are insensible ; but in the immense 

 varieties of odours we are capable of perceiving, our superi- 

 ority is manifest. In hearing, animals are demonstrably 

 inferior. Some of them may be as susceptible to certain 

 sounds, but none are susceptible to the immense variety of 

 sounds distinguishable by our ears. Indeed, when from 

 Comparative Anatomy we learn how much more complex 

 are the Sensational Centres in man, we may be certain that 

 the sensations also will be more various. 



Before quitting our Molluscs, let us for a moment consider 

 the shells with which the vast majority are furnished, and 

 with which all are furnished in their embryonic state. I 

 do not mean that we should lose ourselves in the varieties 

 of a conchologist's collection, nor that we should inquire 

 minutely into the structure of the shell and its mode 

 of growth ; but that we should pause to consider its 

 relation to the great forces of the universe. You may pos- 



