The Origin of the Electric Organs in Astroscopus Guttatus. 147 



that Babuchin (2) came to the conclusion that, inasmuch as the origin, 

 sti-ucture, and functional activity of the pseudoelectric organs, although 

 diminutive and less highly differentiated than those of Torpedo and 

 Qymnotus, nevertheless are fundamentally the same; therefore, "Es 

 existieren keine pseudoelektrischen organe, es gibt nur grosse und 

 starke, kleine und schwache elektrische organe." The term pseudo- 

 electrical organs has since been definitely abandoned and the Mor- 

 myridse and the Rajidse are known as the weak electric fishes. 



In 1880 Fritsch (44) described in detail the electric organs of Malop- 

 terurus and startled investigators by attempting to show that the elec- 

 troplaxes were neither arranged in parallel series, as in all other electric 

 fishes, nor derived from muscle-cells. He tried to prove that the 

 organs in this fish are developed from certain gland-cells in the skin, an 

 observation which aroused much discussion and which never has been 

 substantiated. No investigator has been able, on the other hand, to 

 prove the origin of the organs from any of the muscle-cells, so the mat- 

 ter remains an open question to this day, Avith a possibility of thus 

 bringing Malopterurus into line with the other electric fishes. The 

 peculiar structure of the electroplaxes, however, and the inability to 

 harmonize the direction of the cxu"rent with Pacini's law are facts 

 which can not be denied, and Malopterurus stands as the great excep- 

 tion to the general rules for electric fishes. At any rate, Malopterurus 

 has not sacrificed any of its motor muscles to the formation of the 

 organs and its movements are not in any way hampered, while the 

 electric coat, which completely surrounds the body, forms an effective 

 protection as well as a means of easily capturing its food. Gymnotus 

 and Torpedo, on the other hand, move so slowly that they have to numb 

 their prey at some distance and then follow them up at their leisure. 

 It is doubtful whether the weak electric fishes use their electric organs 

 for either protection or for capturing food, although it is possible that 

 they may capture in this way small Crustacea and other minute inver- 

 tebrates. 



Recently Professor Dahlgren has become interested in certain Amer- 

 ican species of electric fishes. He has published several papers, one on 

 the anatomy and muscular origin of the electric organ of Gymnarchus 

 (32), an African form distantly related to the Moniiyridse, and several 

 on the gross anatomy and habits of the star-gazer, Astroscopus (33, 34, 

 36), a marine teleost of the toad-fish group, a group hitherto unrepre- 

 sented among the electric fishes. In 1906 Dahlgren (36) and Silvester 

 published an account of the adult Astroscopus. The authors had been 

 interested in reports from Charles H. Gilbert and J. A. Henshall 

 (Jordan 64, 65), who reported having felt shocks from the two species 

 Astroscopus guttatus and Astroscopus y-grmcum. Fishermen who were 

 interviewed said that they had always known of the numbing power 

 of these fishes and had often received shocks from stepping on them 

 as they lay buried in the sand. 



