I02 TfiE Ottawa Naturalist. 



have not yet exclusively taken up either muscle or nerve functions, 

 but perform the purposes of both. The metamorphosed substance, 

 soft, transparent, and homogeneous, of the electric organs referred 

 to recall this remarkable tissue as thoughthe muscular tissue in the 

 fishes in question were retrograding as it were, and returning to 

 the early neuro-muscular condition. 



On the other hand, in the eel and the Nile-pike, wc have 

 another type of tissue no less interesting and curious. The gland 

 cells of the' skin, instead of devoting themselves solely to 

 secretion, have metamorphosed their energ}- in such a way as to 

 be effective in the production of electricit}-. They are so well 

 developed in Hlonnyrus as to form quite a compact layer beneath 

 the integument. In the eel they retain their more primitive 

 scattered character. It may be that an unsuspected number of 

 common fishes are possessed of powers similar to those of the 

 eel. A mysterious tremor is said to be felt b)' the patient when 

 a piece of eel-skin is applied to an affected part of the body. 

 Can it be that the electro-motive force in the dried fishes' inte- 

 gument can be again aroused by the damp acid exudations of the 

 human skin? At any rate we have in the surprising properties 

 of the eel's glandular integument not onl)' a key to the inter- 

 pretation of many forms of electric organs in fishes, but possibly 

 an explanation also of the luminous or phosphorescent features 

 which many fishes exhibit. Biologists have perhaps not fully 

 realised the large place which electrical phenomena fill in the 

 complex vortex of animal life. All muscular contractions involve: 

 more or less marked electric phenomena. Muscle we have seen 

 ma}' become essentially electric in its properties, and it now 

 appears that glands may assume the role of electric and possibly 

 phosphorescent organs in fishes. 



