FORMS OF FISHES. 257 



wounded with harpoons, they are dragged on shore with dry and 

 nonconducting pieces of wood, and thus the strange combat 

 ends. 



In no class of the animal kingdom do we find such diversity 

 of form as in that of fishes. Some amongst them are perfectly 

 spherical, others flat or circular ; but generally they are of an 

 elongated oval shape, a figure which enables them with greater 

 celerity and ease than any other to pass through the water. 

 Their viscera are packed in a small compass in a cavity brought 

 forwards close to the head, and whilst the consequent suppres- 

 sion of the neck gives the advantage of a more fixed and resisting- 

 connection of the head to the trunk, a greater proportion of the 

 body behind is left free for the development and allocation of 

 the powerful muscular masses which are to move the gradually- 

 tapering tail, whose lateral rapidly-alternating strokes are its- 

 chief means of progression through the water. We wisely 

 endeavour to imitate this peculiar shape in the construction of 



Skeleton of the Perch. 



our ships, yet the rapidity of our fastest clippers is nothing to 

 the velocity of animals that have been specially formed for 

 natation by an All wise Hand. The energetic action of the tail 

 is assisted by the dorsal (A), caudal (B), and anal (c) fins, which 

 serve by their vertical position to increase the rowing surface, 

 and thus add considerably to the rapidity of motion; while 

 the pectoral (D) and ventral (E) fins, which correspond to the fore 

 and hind limbs of the higher vertebrates, are of the greatest 

 importance in directing the movements of the animal. With 

 the help of these highly flexible organs, fishes can turn about 



