UNVERIFIED DEDUCTIONS. 185 



selection than the origin of the electric organs 

 themselves. He has suggested that this re- 

 markable peculiarity has been developed to 

 insure perfect co-ordination between the elec- 

 tric organs of the two sides of the body, with- 

 out which there could not be perfect unity of 

 action in the electric discharge, whereas while 

 the tissue is merely muscular it is important 

 that the organs of the two sides should act 

 independently of each other. 



Fritsch has also called attention to the fact 

 that the sluggish powerfully electric fishes are 

 carnivorous, and the active feebly electric spe- 

 cies are at least mostly herbivorous. 



More recently still, Professor Engelmann, 1 

 of Utrecht, in a histological study of the elec- 

 tric organs in embryos of Raja clavata, etc., 

 has established in detail the genetic relations 

 between some of the elements of cross-striped 

 muscle-fibre and the lamellae of the so called 

 meandrine or striped layer which, lying be- 

 neath the nerve end-plate in most species of 

 Raja, forms one of the principal constituents of 

 the electric organs in the tail of these fishes. 

 Hitherto little more had been known than that 



1 Th. W. Engelmann, Archiv fur die Gesammte Physiolo- 

 gic des Menschen und der Thiere, Band LVII. pp. 149-180, 

 June 1 6, 1894. 



