164 Descriptive Zoology. . 



"depressed," as with the rays. The flounders are com- 

 pressed, but have turned down on one side. 



Electric Fishes. These fishes have the power of giving 

 an electric shock when touched. The electrical apparatus 

 is a modification of the muscular system, and, like the 

 muscles, is under the control of the nervous system. It is 

 a point to be noted that the electric fishes are devoid of 

 scales. The torpedo of the Atlantic coast and of the 

 Mediterranean belongs to the rays. An African catfish 

 has the same power, and in South America is found the 

 electric eel. It is said that in South Africa the natives 

 drive herds of horses into the pools, and after the electric 

 eels have exhausted their " shocking power " on the horses, 

 the eels may be caught and handled with impunity. 



Colors of Fishes. The colors of fishes are due to two 

 factors, the nature of the scales and the pigment in the 

 epidermis. The scales often are striated or polished to 

 give various colors, especially the gleam so often seen on 

 the sides of a fish. Aside from this kind of appearance the 

 color is chiefly due to pigment. As in most animals, the 

 color 's darker on the back than below, where we often find 

 white. The olive or dark back of most fishes makes it 

 difficult to see them when looking down into the water, 

 while the white color beneath might make a fish less con- 

 spicuous to an enemy below him. In the breeding season 

 many fishes, especially the males, assume much brighter 

 colors, most accented on the fins. Many fishes, notably 

 catfishes, change their color considerably in conformity 

 with their surroundings, like the amphibians and lizards. 



Care of the Eggs and Young. Most fishes give no care 

 whatever to the eggs or young. Some deposit the eggs in 

 a place of comparative safety. The stickleback builds a 

 nest for the eggs and the male defends them carefully. 



