634 NATURAL HISTOKT OF AQ0ATIC ANIMALS. 



spawn iu fresh, water; that many full-grown individuals, but not all, descend rivers during the 

 winter months, and that some of them at least must spawn iu brackish water or in deep water in 

 the sea; for in the course of the summer young individuals from three to five 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 firnia to waters 

 shut off from all communication with rivers. Such emigrations have long been known by tlie 

 name 'JEel-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. No 

 naturalist has ever observed these fishes in the act of spawning, or found mature ova; and the 

 organs of reproduction in individuals caught in fresh 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." 



Migrations op Eels. — In attempting to review this subject I am sure I cannot do better 

 than to translate at length a communication just received from my friend Dr. Berthold Benecke, 

 professor in the University of Konigsberg : 



"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 localities 

 in G-ermany completely exterminated them. Since the Eel is everywhere known as a greedy 

 robber, many accounts have been given of their 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 Bel 

 also comes out of the water in the night-time into the fields, where he can find pease, beans, or lentils.' 

 This statement was contradicted in 1666 by Baldnef,i who writes concerning the Eel: 'They eat 

 fish, do not come on the land, and do not eat pease, but remain in the water always, and are 

 nocturnal animals.' 



" Forthwith, new statements were made which tended to show the actuality of the wanderings 

 of the Eels in the pea-patches. For instance, Bach, in his ' Natural History of East and West Prus- 

 sia,' published in 1784, maintained that Eels frequently were caught in the pea-patches in the 

 vicinity of the water, where they fed upon the leaves, or, according to other accounts, upon the 

 pease themselves, and continues : ' These movements explain the paradoxical fact that in Prussia 

 and Pomerania fish have been caught upon dry land by the use of the plow, for the peasants, 

 in warm nights when the Eels are in search of the pease, towards morning when it is Jiot yet day 

 make furrows with the plow between them and the water, and these are the nets in which the 



•Reoht natiirliche Besohreibung imd Abmahlung der Wasser-Vogel, Fischen, vierfiissigen Thier, lusecten und 

 Gewirm, so bey Strassburg in deu Wassern sind, die icb selber geschossen und die Fisoh gefangen, auch alles in meiner 

 Hand gehabt. Leonhard Baldner, Fischer und Hagmeister in Strassburg gefertigt worden 1666. Manuscript. (Cited 

 by von Siebold, "Susawasserfische von Mitteleuropa," Leipzig, 1863.) 



