462 PARENTAL CAEE AMONG FRESH-WATER FISHES. 



but it is not known when or how they are hiid. The fishermen of tlie 

 Nile assert that the fry are carried in the mouth of a parent. 



Naturally a fish possessed of such remarkable attributes as the raad 

 attracts general attention, and nuist be at least tolerably well known 

 to most of the inhabitants of the country in whose waters it dwells. 

 The species was known to the ancient Egyptians, and, according to 

 Gotch, it was delineated on the interior walls of Ti, estimated to have 

 lived five thousand years before the Christian era. 



It was doubtless used as a remedial agent from early times. An 

 Arabian physician of the twelfth century described the elfects pro- 

 duced by the fish. It was descril)ed likewise in a cou})le of chapters 

 in 1()25 in " Purchas, his Pilgrimes " (pp. 1183, 1545), under the 

 name of torpedo. Its electrical power is made use of for sanitary 

 and invigorating purposes by the African natives, who share with 

 many of their European brethren the belief that electricity has 

 peculiar efficacy and restorative virtues. A child may be put into a 

 tub containing a raad and kept for a time in spite of its yells and 

 cries, by the mother, who sacrifices her tenderness of feeling to the 

 desire for the welfare of her offspring. 



Not all the natives in the country of the electric catfishes are fa- 

 miliar with or know of their power. Ignorance is sometimes dis- 

 played where it would be least expected. One of the party of a 

 Belgian official in the Kongo State on one occasion played a practical 

 joke on his '•"chef;" a good-sized fish was caught and carried alive 

 to the Kongo chef; he took it and, knife in hand, prepared to skin 

 it, but as soon as his knife touched the skin the man experienced a 

 shock which evoked shrieks of amazement and pain and hurled him 

 to the ground, where he remained prone and bewildered for some 

 time. 



THE CALLICHTHYIDS. 



Related to the Silurids, but forming a peculiar family, is a group 

 of fishes restricted to tropical America ; it is that of the Callich- 

 thyids. 



The Hassars or Cascaduras, otherwise denominated the Callich- 

 thyids, have a superficial resemblance to the catfishes, but are distin- 

 guished from them, as well as from all other fishes, by a peculiar coat 

 of mail composed of lateral rows of narrow vertically extended 

 plates, two rows on each side, which interlock along the lateral line 

 and cover completely the sides. The head has a special system of 

 plates, and the operculum is well developed; the mouth is inferior 

 and small and the intermaxillary bones much reduced in size; the 

 lower lip is everted; the nuixillary barbels doubled; the dorsal fin is 

 anterior and has a strong sj^ine, and a spine also fronts the adipose fin ; 



