IIO MAMMALIA. 



A large number of the Adirondack lakes are heavily bordered 

 with a dense frontage of arbor vita^ (here called "white cedar"), 

 which so overhangs the water that the lower limbs barely clear 

 the surface. Around many of these lakes all the lower branches, 

 up to a certain height, are dead, so that on viewing the shore 

 one is struck with the strange appearance of a sharp cut line, about 

 the height of a man's head, extending partly, or entirely, around the 

 lake. Above it the dense foliage presents an almost continuous and 

 unbroken front, impenetrable to the eye, while below it not a green 

 sprig can be seen, the dead limbs and branches remaining in the 

 form of a broad belt. 



The cause of this phenomenon long remained a mystery, and many 

 and amusing theories have been advanced for its explanation. It 

 has been supposed that some unusual and unknown agency operated 

 to produce a great overflow of these lakes, and that the present green 

 line indicates the high-water mark of this unrecorded inundation, the 

 branches below it having been killed by the water or ice. Were there 

 no other reasons for disbelieving this hypothesis, its absurdity is de- 

 monstrated by the fact that on many of the larger lakes the line is 

 confined to one side. The only other theory, so far as I am aware, 

 that is worthy of refutation, was advanced by no less distinguished a 

 gentleman than Mr. Verplanck Colvin, Superintendent of the Adiron- 

 dack Survey. Mr. Colvin's theory is, that the snow which is blown 

 off from the ice, on some of the larger lakes, and is sometimes piled 

 in drifts in certain places along the borders, buries the lower limbs 

 of the cedars; and he thinks that 1 this snow " in some unfavorable 

 season, becoming compact and icy, had killed the enclosed evergreen 

 foliage. "* The fallacy of this view is proven, I think, by the follow- 

 ing facts : ist, branches on the opposite or shore side of these very 



the leaves and stems of the "bunch berry" or dwarf cornel (Corn us Ctiiiiiitcnsis), a small amount of 

 winrergreen (Gaultheria procuml>cns), and a few leaf-stems of the mountain ash (Pyn/s .-[incricana) 

 while throughout the mass were scattered numbers of beech-nuts with the shucks on. 



* Report of Adirondack Survey, 1880, p. 162. 



