516 LIVING TORPEDOS IN BERLIN. 



a thread through the dorsal or ventral skin of the preparation and 

 pulled the preparation into the tube by the thread. Any ends 

 which might happen to project were cut off. I often helped to get 

 it into the tube by sucking. In doing this, it happened that 

 I sucked the preparation quite through the tube into my mouth. 

 To my surprise, I found that the organ was quite insipid, 

 without a trace of the salt taste I had expected in accordance 

 with Boll's statement on' the Liquor cerebrospinalis of the Tor- 

 pedo 1 . 



According to Boll's estimate, the tissues of the Torpedo con- 

 tain a salt solution of 2.5 per cent., so that only a solution of 

 sodium chloride of this strength would be 'physiological' to them. 

 According to Leon Fredericq the blood of the Octopus vulgaris 

 and Astacus marinus contains about four times more salts than 

 that of mammals. Hence I suspected that the tissues of marine 

 animals, especially of sea fishes, would be richer in salt than those 

 of fresh-water animals, and that they would also conduct better 

 accordingly. They would thus be more strongly affected by the 

 current curves with which a Torpedo shock fills the sea around it, 

 than if they had only the same proportion of salt as fresh-water 

 animals, for these curves are attenuated in a badly conducting body 

 plunged in the sea 2 . That it would be of service to the Torpedo if 

 its own organ conducted better, seemed quite obvious. But the 

 state of the case is otherwise. 



First of all, it was found that the tissues of sea fish are not per- 

 ceptibly salter than those of fresh-water fish. It could not be 

 concluded with certainty from Atwater's and Konig's tables that 

 sea fish are richer in salt, and Weyl found that the organ of the 

 Torpedo yielded only a little more ash than the muscle flesh of 

 river fish (p. 43 7) 3 . But Fredericq had observed what had 

 escaped me, that the characteristic which he had recognized at the 

 date of my first communication in the invertebrate marine animals, 

 is absent in sea fishes Trackinus spec., Solea vulgaris, G. Aeglefinus 

 (a shark) and he was thus led to regard the circumstance that the 

 amount of salt contained in the fish is so independent of the 

 medium in which they live, as an indication of their higher organi- 



1 Monatsberichte der Akademie, 1875, p. 710; Archiv fur Anatomic, Physiologic, 

 1875, p. 463, note. 



3 Untersuchungen, &c., pp. 133, 415. 



3 Comp. also Almen, in Maly's Jahresbericht iiber die Fortschritte der Thier- 

 Chemie, vol. vii. 1877, p. 308. 



