THE SHORES OF BRITAIN. 81 



ship, worthy of the Divine hand that formed it. 

 The scales of some fishes are so minute as to be 

 with difficulty distinguishable; such as those of the 

 Eel: to procure these for microscopical examination, 

 "take a piece of the skin of the Eel that grows on 

 the side, and while it is moist spread it on a piece 

 of glass, that it may dry very smooth ; when thus 

 dried, the surface will appear all over dimpled or 

 pitted by the scales, which lie under a sort of cuticle, 

 or thin skin: this skin may be raised with the sharp 

 point of a penknife, together with the scales, which 

 will then easily slip out, and thus you may procure 

 as many as you please."* 



The limbs of fishes differ greatly in appearance 

 from those of terrestrial animals; consisting, as to 

 the portion external to the body, of slender spines, 

 sometimes cartilaginous and jointed, at others bony 

 and simple, united by means of a thin membrane 

 stretched from one to the other. Generally there 

 are two pairs on the under part of the body, which 

 are called the pectoral and the ventral fins, and re- 

 present respectively the fore and hind legs of qua- 

 drupeds, or the wings and feet of a bird. Besides 

 these, there are one or more perpendicular fins along 

 the back, called the dorsal, and one below the body, 

 near the tail, called the anal ; but the main instru- 

 ment of motion is the broad, perpendicular fin, which 

 terminates the body, often called the tail, but, more 

 correctly, the caudal or tail fin. To rightly under- 

 stand the motions of a fish,*ve must bear in mind 

 that it is immersed in a fluid which is of little less 



* Martin's Micrographia Nova, p. 29. 



