VENOM, ELECTRICITY, LIGHT, AND SOUND 145 



of that organ and later of all the muscles of the body, death 

 finally resulting from paralysis of the heart and asphyxiation. 

 No antidote to the poison is known, and the only treatment 

 consists in administering a strong emetic and giving suitable 

 stimulants to prevent collapse. Such sickness is not to be 

 confused with ordinary fish poisoning so prevalent in the tropics, 

 which is not caused by any specific poison in the living flesh, 

 but by the formation of other alkaloids known as ptomaines 

 due to the action of bacteria in the decomposing tissues. These 

 poisonous bacteria may be destroyed by cooking, but the 

 alkaloids present in the flesh of a Puffer are not affected by the 

 highest temperature. Other fishes, although not normally 

 harmful, may become highly poisonous at certain seasons, and 

 especially at the breeding season, when it is dangerous to eat 

 the roes. Others again, like the Wrasses {Labridae) and Parrot- 

 fishes (Scaridae), owe their poisonous properties at certain times 

 to the food which they have been eating, having devoured 

 poisonous mussels, echinoderms, polyps, and the like, them- 

 selves containing the deadly alkaloids. In many Eels [Apodes) 

 the serum of the blood is said to be highly poisonous, but as 

 the venom is destroyed by the gastric juices these fishes may be 

 eaten with impunity. The futility of prohibiting as food any 

 species suspected of causing poisoning was demonstrated by 

 the action taken by the Cuban Government in drawing up a 

 list of forbidden species. As fresh cases of poisoning occurred, 

 new names were added to the list, which finally included all 

 the best food-fishes of the West Indies ! 



Still more remarkable than the poisonous are the electrical 

 properties of fishes. Among those forms provided with special 

 organs capable of generating an electric discharge, the following 

 are deserving of special mention: the Torpedoes, Ray- like 

 fishes of tropical and temperate seas; the Skates and rays; 

 the Mormyrids ; the Electric Eel of the Orinoco and Amazon 

 river systems ; the Electric Cat-fish, a fresh-water species widely 

 distributed in Africa; and the marine Star-gazers. This list 

 includes species by no means closely related, and found both in 

 salt and fresh water. 



In the Torpedo or Electric Ray {Torpedo) two organs are 

 present, lying on either side of the disc-like body, between the 

 head and the greatly enlarged pectoral fins (Fig. 61). Each 

 is a large, flat body, made up of a number of upright hexagonal 

 tubes or columns, separated from one another by walls of 

 fibrous tissue. Each column is filled with a clear, jelly-like 



