104 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



Sucli is the energy of these little animals that they continued to find 

 their way in immense numbers to Loch Erne. 



In the little eels which ascend the rivers there are no traces of sexual 

 organs, but in the fresh water they develop only into females. One of 

 the most recent observations made by Dr. Pauly, in Munich, would 

 appear to contradict this idea, since he discovered male eels among the 

 fish which were brought with a lot of young eels to Hliningeu, were 

 kept there for two years in ponds, and were finally released in the fish 

 pond of Court-Fisherman Kaufler. We should bear in mind, however, 

 that these young eels were captured at the mouths of fresh rivers in 

 brackish water ; and that among the numerous small eels which swim 

 in the brackish water there must be many larger specimens, in which 

 the male organs have already begun to develop. Such are doubtless 

 those which were sent in the male condition to Hiiningen and Munich, 

 and were there recognized as males. This presumption can be set aside 

 only if male eels shall hereafter be found among the fish which are 

 caught in the upper part of rivers in the condition of young fry. 



Concerning another imi)ortant fact which is connected with the 

 movements of the young fry of the eel, I became acquainted last year 

 (in the course of an exploration of the waters of the district of Kouitz- 

 kunde) with the river Brahe, at Mlihlhof, above Eittel, where a high dam 

 was built in 184G and 1847 for the purpose of watering a large system 

 of meadows by the overflowing of the stream. Below the dam is an 

 inclined plane (constructed of boards), about 300 feet long, built for the 

 j)urpose of preventing the water, which rushes out when the sluice-gate 

 is opened, from washing away the bottom of the stream and its banks. 

 This plank floor consists of two layers, the lower one of 2-inch, the upi^er 

 one of 3-inch boards. The grade of the dam at Mlihlhof (33 feet 3 

 inches) has entirely cut ofi" the ascent of the fry of the eel into the upper 

 part of the Brahe and the lakes tributary to it, and the number of eels 

 caught above the dam — which was formerly very considerable — has 

 become reduced almost to nothing. In tbe year 1847 the construction 

 of the dam and the inclined plane was completed ; in 1852 the upper 

 layer of the planks on the plane had warped and sprung up in mauy 

 IDlaces, so that it had to be torn up for repairs. The cause of the warp- 

 ing was immediately discovered: thousands of eels — as thick as a man's 

 finger — somewhat flattened in shape, and, on account of the absence of 

 light, of a pure white color, filled the space between the two layers of 

 planks, and their united pressure from beneath had caused the upper 



to six inches long, return in immense numbers. The basin of the Still River Falls, 

 near Colebrooke line, is for several days alive with them. They may be seen labor- 

 iously crawling up every rock which is moistened by the spray of the fall, and en- 

 deavoring to reach their ancestral lake or dam. At the foot of the Niagara Falls this 

 phenomenon may be witnessed on a large scale at the same season of the year or 

 later, and probably in other places where the fall is too high and the cuirent too 

 swift for the young eels to stem it without contact with the rocks. — Annals of Win- 

 chester, Conn., Boyd, p. 26. 



