102 The American Naturalist. [January, 



course of the ice scratches on the summit of the watershed south of 

 this, between the lake and the Ohio River. The reason for this change 

 of direction can readily be seen by a little attention to the physical 

 geography. The high lands to the south of the lake rise about seven 

 hundred feet above it. When the ice period was at its climax, and 

 overran these high lands, it took its natural course at right angles to 

 the terminal moraine, and il< w .1 si.uth-ea>t, according to the direction 

 indicated by the scratches on the summit. But when the supply of 

 ice was not sufficient to overrun the high lands, the obstruction in 

 front turned the course, and the result was a motion towards Toledo 

 and the Maumee Valley, where, in the vicinity of Fort Wayne, an 

 extensive terminal moraine was formed. The grooves on the islands 

 near Sandusky were produced during that stage in the recession of the 

 great ice-sheet. 



The groove preserved is only a small portion of what still exists. 

 But it would be too much to ask to have more given by the company. 

 As it is, the public spirit shown by the directors, gathered from Boston 

 to Duluth, has rarely been equaled by a similar corporation. Quarry- 

 ing has already proceeded nearly all around this specimen, and soon 

 the monument preserved will be a monument indeed; the groove 

 being left to cap a pedestal about thirty feet high, and conspicuous 

 from every side. About one-half the surface will be cleared of debris, 

 so as to show fifty feet of the length of the groove, while the other half 

 will remain as it is, beneath its protective covering of pebbles, gravel, 

 sand, and mud, which acted as the graving tools in the firm grasp of 

 ice. In this condition it is to be presented to the Western Reserve 

 Historical Society of Cleveland to remain for the admiration and 

 instruction of all future generations. I trust the citizens of the vicin- 

 ity will appreciate the noble gift enough to occasionally visit the place 

 and receive the deep impression? it is so well calculated to make. 



