146 ZOOLOGY. 



together ; consistently with the short and fixed condi- 

 tion of this part in all the whale tribe. The remainder 

 of the spinal column is strongly and perfectly formed, 

 flexible, and continued as a tail through the centre of 

 the terminal fin, or " flukes." The ribs and breast- 

 bone are as perfect as in quadrupeds ; but collar-bones 

 are wanting ; as occurs also in a large proportion of land 

 mammals, where the presence of these bones is not 

 essential to the functions of the anterior extremities. 

 The bones of the arms coincide with those of digitated 

 quadrupeds : they have, however, no movement on each 

 other, excepting at the shoulder-joint, and their form 

 is compressed, and concealed beneath a continuous sur- 

 face of dense skin, which gives them the appearance of 

 fins, and admirably adapts them for their function as 

 paddles, or swimming-paws. It is in the posterior part 

 of the skeleton that the most remarkable deficiency is 

 perceptible ; for not a vestige exists of posterior ex- 

 tremities ; nor more than small and rudimental bones of 

 the firm bony fabric, or pelvis, to which they should be 

 attached. 



The vital organs and their functions, in cetacea, bear 

 a close analogy to those of quadrupeds ; or depart from 

 the resemblance, only in such points as may distinguish 

 one from another order of mammiferous animals. The 

 organs of the senses are so little developed in this 

 family, as to lead to the belief that their functions are 

 feeble. The nerves of smell are absent in all the known 

 kinds, excepting the true Whales, or Rorquals ; and in 

 these latter genera they are of diminutive size. The 

 eyes, though well constructed for aquatic vision, are 

 invariably small, deeply planted in the head, and can 

 command but little oblique vision. The ear opens ex- 

 ternally as a very minute orifice, and has no external 



