BULLETIN OF THE UNITED STATES FISH COMMISSION. 77 



ichthyology, contributed to the Encyclopedia Britaunica, Giiuther 

 ^yl■ites : 



"Their mode of propagation is still unknown. So much only is certain, 

 that they do not spawn in fresh water; that many full-grown individ- 

 uals, but not all, descend rivers during the winter months, and that 

 some of them at least must spawn in brackish water or in dee]) water in 

 the sea; for in the course of the summer young individuals from 3 to 5 

 inches long ascend rivers in incredible numbers, overcoming all obstacles, 

 ascending vertical walls or flood-gates, entering every larger and swollen 

 tributary, and making their way even over terra firma to waters shut off 

 from all communication with rivers. Such emigrations have long been 

 known by the name '■Eel-fairs\ The majority of the eels which migrate 

 to the sea appear to return to fresh water, but not in a body, but 

 irregularly, and throughout the warmer part of the year. Xo naturalist 

 has ever observed these fishes in the act of spawning, or found mature 

 ova; and the organs of reproduction in individuals caught in fresk 

 water are so little developed and so much alike, that the female organ 

 can be distinguished from the male only with the aid of a microscope." 



VII. BeNECKE on the general natural HISTORY OF THE EEL. 



In attempting to j)resent a review of this subject I am sure I cannot 

 do better than to translate at length a communication just received from 

 mj- friend Dr. Berthold Benecke, professor in the University of Konigs- 

 berg : 



"The coloration of eels varies greatly not only in different localities, 

 but in the very same places: the back may be dark blue or greenish 

 black ; the sides, lighter blue or green ; the belly, white ; sometimes the 

 back is only slightly darker than the sides ; sometimes there are olive 

 green individuals with a golden-yellow band upon their back, sometimes 

 they are entirely golden-yellow and, very rarely, entirely white. The 

 eel lives in deep quiet waters with muddy bottom; it burrows out holes 

 and tunnels in which it rests quietly during the day, while at night it 

 comes out in search of food. From^the deck of a steamer passing through 

 rivers or canals one may see upon the banks, which are laid bare by the 

 waves produced by the motion of the vessels, numerous eels with half 

 of their bodies projecting from their lurking holes. 



"The eel feeds upon all kinds of small water-animals, and may be 

 found on the spawning places of other fish in great troops, going there 

 for the purpose of feeding upon the eggs. They feed also upon crabs at 

 the period when they are shedding their shells, and have in many local- 

 ities in Germany completely exterminated them. Since the eel is every- 

 where known as a greedy robber, many accounts have been given of 

 theu' wanderings, in which they have made their way into the pea- 

 patches to feed upon pease. The oldest reference of this kind is that of 

 Albertus Magnus, who remarks in his book of animals, published at 

 Frankfort- on-the-Main in 1545 : ' The eel also comes out of the water iu^ 



