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facilitate and extend the range of those species of rep- 

 tiles and fishes whose habitat is chiefly in spring's and 

 small brooks. Where the grounds are covered with 

 dense forests, which prevent evaporation from their 

 surface, and with logs and leaves, which prevent the 

 waters from passing quickly off into the streams, it is 

 quite common to find, not in level countries only, but 

 in mountainous regions, two, or more, streams originat- 

 ing from the same swamp, or pond, or fountain, and 

 running off in opposite directions, and through different 

 large rivers, to the ocean. Several cases of this kind 

 are well known to have existed among the Green 

 Mountains in Vermont, through which trout and other 

 small fishes, and reptiles, might pass without difficulty 

 from one side of the mountain to the other from the 

 tributaries of the Connecticut into the tributaries of 

 Lake Champlain, and vice versa. One of the most 

 remarkable of these was in Williamstown, near the 

 centre of the State. The lowest summit level between 

 Connecticut river and Lake Champlain is in that town, 

 in a considerable valley, extending nearly north and 

 south through what is called the height of land, and 

 is 908 feet above the level of the ocean. From the 

 eastern slope, which forms one side of this valley, and 

 directly against the summit level, there descended into 

 it a considerable trout stream; but just before this 

 stream reached the highest point in the bottom of the 

 valley, towards which it was tending, it divided itself 

 naturally into two nearly equal parts, one of which 

 flowed southward, through White river, into the Con- 

 necticut, and the other northward, through Winooski 

 river, into Lake Champlain ; thus opening to fishes of 

 considerable size an easy communication between the 

 two slopes of the Green Mountains., 



