LECTURE IV. 141 



thick fins, while the tail, which is divided into two 

 horizontal lobes, is merely muscular and ten- 

 dinous, being void of any bones analogous to 

 the feet in the rest of the Mammalia ; those bones 

 being only to be found in the fms or fore-feet. 



The general appearance of the Cetaceous 

 Mammalia or Whales so much resembles that of 

 a fish, that it is very natural for any one to sup- 

 pose that they should be classed among that tribe 

 of animals, and not with the rest of the Mam- 

 malia ; and indeed so far has this compliance v/ith 

 popular custom been followed, that most natu- ~ 

 ralists, till the' institution of the Linn^an System, 

 gave them the appellation of Fishes, Thus, ex- 

 clusive of the more early writers, the celebrated 

 Ray and Willoughby considered them in this view, 

 and commenced their History of Fishes with that 

 of Whales. Nay even Linnaeus himself, in his 

 well-known work the Fauna Suecica, as well as in 

 some of the earlier editions of the System a Na- 

 turae, arranged them under the class of Fishes. 

 But, since their whole interior structure agrees 

 with that of the Mammalia j since they have lungs 

 and breathe, since they have vv^arm blood, and a 

 heart resembling in conformation that of Qua- 



