248 MINUTE MARVELS OF NATURE 



seas, and of little commercial value, provide pretty 

 objects for the microscope ; Fig. 169 illustrates 

 this. The skin of these fishes is sometimes used 



Fig. 167. Hairs of .1 iiurnlile bee 



as a substitute lor sand-paper, and employed by 

 joiners for polishing the surface of fine woods to 

 show up the grain. 



But, as every microscopist may not meet with 

 a dog-fish, let us glance at other and more familiar 

 examples of fish-skins. For instance. Fig. 170 

 shows a small portion of the skin of the sole, a 



