68 COMPARATIVE ANATOMY 



anatomists seem to hare been the first to throw out , 

 difficulties in the way of this helief, by discovering 

 that in the majority of the species the olfactory 

 nerve does not exist, and that there is no opening 

 in the skull by which that nerve can pass. Cuvier's 

 words, in 1823, are, in the Cetacea there is an 

 absence of the olfactory nerve and the usual organs 

 of smell. (Os. Foss. v. 235; see too, Comp. Anat. 

 vol. ii. 683). Ray and Rondelitius were aware of 

 this fact as it respects the dolphin, yet the latter of 

 these authors still maintains that it has a very acute 

 sense of smell, " as Aristotle testifies and experience 

 manifests ;" a conclusion in which few, now-a-days, 

 will be inclined to follow him. The same deficiency 

 has been ascertained respecting the porpoise genus ; 

 and Cuvier's words are, " probably the other Ce- 

 tacea likewise want them, as they have no sethmoidal 

 holes." (Comp. Anat. ii. 199.) This, however, 

 only shows the danger of reasoning from ana- 

 logy in this order of animals, whose diiferences ap- 

 pear to be endless. " I believe," says Mr. Hunter, 

 " the olfactory nerve is peculiar to the mystwetus and 

 rorqual, the large and small whalebone whales" 

 (Loc. Cit. 429) ; and such an observation was more 

 than sufficient to set the ingenuity of this extra- 

 ordinary man to work. How do animals smell ? 

 have aromata any other vehicle than air ? how can 

 water be smelt ? and according to him, water, in 

 the Cetacea, never comes into contact with the 

 sinuses in which their olfactory nerves are dis- 

 tributed ; and their perceiving smells, through the 



