ELECTRICAL ORGANS. 



8B 



EO 



Electrical organs,* the function of which is to develop con- 

 siderable quantities of electricity, are found in some fishes. 

 They occur in different parts of the body and in fishes belong- 

 ing to quite different groups (e.g. Torpedo and Hypnos among 

 Elasmobranchs, and Gymnotus and Malapterurus among 

 Teleoste a n s ) . 

 They differ 

 both in struc- 

 ture and po- 

 sition in the 

 body, but they 

 always consist 

 o f peculiarly 

 modified cross- 

 striped muscu- 

 lar tissue. 



In Torpedo 

 (Fig. 45) they 

 are placed be- 

 tween the bran- 

 chial pouches 

 and the anterior 

 cartilages of the 

 pectoral fins, 

 and occupy the 

 whole space be- 

 tween the dor- 

 sal and ventral 

 integument. 

 They consist of 

 vertically ar- 

 ran g e d col- 

 umns, sup- 

 ported by walls 



of connective tissue, and divided by horizontal septa of the 

 same material into a number of compartments placed one 



FIG. 45. Torpedo with electric organ EO and brain exposed (after 

 Gegenbaur), dorsal view. On the right side the dorsal surface 

 only of the organ is exposed ; on the left the nerves which supply 

 it are shown, br branchial sacs ; Gr sensory canal tubes of the 

 skin ; Le electric lobe of the brain ; o eye ; Tr trigeminal nerve ; 

 V vagus nerve. 



* Fritsch, Die electr. Fische, Abt. 1 and 2, Leipzig, 1890. Ballowitz, 

 Electr. Organ v. Torpedo, Arch. f. mic. Anat., 42, 1893. Sanderson 

 and Gotch, Elect. Organ of Skate, Journ. Physiology, 10, 1889. Ewart, 

 Electric Organ of Skate, Phil. Trans., 1888 * 1892. 



