540 THE OCEAN WORLD. 



Ray-fish of all kinds are inhabitants of the deep sea, but they 

 change according to the seasons. While stormy weather prevails, 

 they hide themselves in the depth of the ocean, where they lie in 

 ambush, creeping along the bottom. But they do not always live 

 at the bottom. They rise occasionally to the surface far from the 

 shore, eagerly chasing other inhabitants of the deep, lashing the 

 water with their formidable tails and fins, springing out of the water, 

 and making it foam again under their gambols. 



When pursuing their prey the rays employ their great pectoral 

 fins, which resemble wings, and are aided by a very delicate and 

 mobile tail ; they beat the waters in order to fall unexpectedly upon 

 their prey, as the eagle swoops down upon its victim. It may thus 

 be called the king of fishes, as the eagle is the king of birds. 



The family TorpedinidcE contains the genus Torpedo. The Electric 

 Ray, Torpedo marmorata (Fig. 360), has considerable analogy with 

 the Ray. Its flattened body forms a roundish disc, beyond which its 

 rays form large pectoral fins ; but the humeral girdle which carries 

 them, carries also, in a great hollow, a most singular organic apparatus, 

 which possesses the property of producing violent electrical commo- 

 tions. This apparatus is placed in the interval between the end of 

 the muzzle and the extremity of the fin, and completes the rounded 

 disc of the body. The mouth is small, the slit crosswise ; the jaws 

 naked ; the teeth in squares of five. The eyes are small ; behind 

 them are two star-like spiracles. On the lower or ventral surface 

 there are two rows of small transverse slits, openings of the branchial 

 sacs, like those of the rays. The tail is thick, short, and conical, 

 carrying part of the ventral, and terminating in a sort of caudal fin. 

 On the back are two small, soft, and adipose fins. The skin is 

 smooth ; the colour varies with the species ; generally it is reddish- 

 brown, with eye-like spots of a deep blue in the centre, sometimes 

 azure, and surrounded by a great brownish circle, the spots being 

 five or six. These curious fishes are found in the Channel and on 

 the shores of the Mediterranean. 



The electrical effects produced on the fisherman who seize them 

 were noted from early times ; but Redi, the Italian naturalist of the 

 seventeenth century, was the first who studied them scientifically. 

 He caught and landed one of them with every precaution. " I 

 had scarcely touched and pressed it with my hand," says the Italian 

 naturalist, " than I experienced a tingling sensation, which extended 

 to my arms and shoulders, which was followed by a disagreeable 

 trembling, with a painful and acute sensation in the elbow joint, 

 which made me withdraw my arm immediately." 



