152 



ZOOLOGY. 



times to swim at others to walk on the soil ; the otter also 

 furnishes a good example of this mechanism. But nature does 

 not for all this depart from her great plan in the construction 



Fig. 105. Skeleton of the Seal.* 



of animals ; the skeleton of the hand and foot of the seal 

 resembles ours (Fig. 105), admitting that in some, as in the 

 whale, the number of phalanges appears to exceed that of 

 mammals generally, and that the fingers themselves seem to 

 be replaced by a number of osseous pieces, reunited under 

 a common integument, as is seen in the fins of fishes. 



Fig. 106. The Flying Fish (the Dactylopterus) . 



294. The structure of the organs which enable an 

 animal to fly, has much analogy with the fins generally ; 

 thus there are fishes (Fig. 106) which use indifferently for 

 progression in air or water their pectoral fins. 



* The bones are lettered as in Fig. 95. 



