98 The Ottawa Naturalist. 



which are very variable in position, sometimes being located near 

 the head, at other times in the tail, while a new and hitherto 

 unsuspected type of electrical organ is the scattered glandular 

 form, which recent investigations have shown to be spread in 

 the skin of one of our commonest fishes. Naturalists have 

 hitherto been unaware of the fact that the common eel of our 

 rivers and lakes is really an electrical fish. It is possible that 

 extended studies will reveal many more common species en- 

 dowed with this remarkable property. 



The most complex form of electrical organ is that of the 

 electric ray 7"t';^<?c/(3 of which several species exist. Five years 

 ago I secured a living torpedo during an official survey on the 

 Kerry coast, Ireland : an interesting capture when it is noted 

 that Thomas Pennant a hundred years ago says of this fish that 

 it " is very rarely taken in British Seas ; the only one we ever 

 heard of being took off the county of Waterford." 



I found that the Irish fishermen stood in dread of it, called 

 it a Mum Ray, a corruption no doubt of Numb or Cramp Ray; 

 but begged for the liver of the fish, to which they attributed 

 almost miraculous curative qualities. It was a clumsy ill-looking 

 creature, and unlike the Skate was thick and fleshy at the lateral 

 margin, ro.und in front and lacking the pointed rostrum or snout. 

 In the dirty ochre-coloured skin a rude hexagonal pattern 

 appeared indistinctly, and on dissection, was found to correspond 

 to the columns of modified soft muscle which constitute the 

 electrical organs. They have been aptly compared to a col- 

 lection of Voltaic piles, each consisting of electric plates of trans- 

 parent homogeneous substance and invested by tendinous 

 connective tissue, which sends alternating extensions between 

 the plates. Over eleven hundred of these hexagonal columns 

 are said to have been counted in a torpedo weighing seventy 

 pounds. Five large nerve trunks pass from the medulla 

 oblongata, on each side, to the organs, dividing up into 50,000 

 or 60,000 separate nerve fibres. The nerve terminations in the 

 electric plates were found by Fritsch to precisely resemble those 

 fn muscular tissue. The organs occupy the entire thickness of 



