May 6, 1898.] 



SCIENCE. 



627 



general nature of the soil — not merely the 

 surface soil, but the underlying beds. 



The professional botanist will find these 

 notes, if new in themselves, merely illus- 

 trative of general laws long familiar to 

 him ; but they are written in the hope that 

 others may find them interesting, and may 

 perhaps be stimulated to make similar ob- 

 servations elsewhere. It is surely desirable 

 for horticulturists to pay more attention to 

 such matters when selecting land and 

 choosing what to grow upon it. 



t. d. a. cookeeell. 



Mbsilla Park, N. M. 



CURRENT NOTES ON PHYSIOGRAPHY. 

 THE NIAGARA GOEGE. 



"When the gorge of Niagara was first as- 

 cribed to work of the river, it was tacitly 

 postulated that the volume of the water 

 and the rate of recession of the falls had 

 been constant. This postulate gave way 

 before the suggestion that variations in 

 river volume may have occurred dui-ing the 

 disappearance of the ice sheet. Now it is 

 attempted to correlate these variations in 

 volume on the one hand with the retreat- 

 ing ice front, the northeastward elevation 

 of the land, and the temporary discharge 

 of the upper great lakes across Ontario, 

 and on the other hand with the breadth 

 and depth of the gorge. A recent paper by 

 Taylor on the ' Origin of the Gorge of the 

 AVhirlpool Rapids at Niagara ' {Bull. Geol. 

 Soc. Amer., IX., 1898, 59-84) explains the 

 narrow part of the gorge, where it is crossed 

 by the railroad bridges and occupied by the 

 Whirlpool Eapids, as the work of the dis- 

 charge of Lake Erie alone — that discharge 

 being called the Erie-Niagara River — -while 

 the upper lakes ran to the St. Lawrence by 

 the Nipissing-Mattawa channel, eastward 

 from the then expanded Georgian Bay. 

 Before the ice sheet had retreated far enough 

 to open this outlet the upper lakes dis- 

 charged through Erie, and the large vol- 



ume of Niagara at that time caused the 

 erosion of the wider gorge and deeper gorge 

 just below and above the Whirlpool. 



It is thus implied that the channel of De- 

 troit River must have been laid dry while 

 the Erie-Niagara was cutting its narrow 

 gorge, and of this Taylor has found good 

 evidence in the depth to which the valleys 

 of small tributaries of the Detroit are 

 eroded below the present river surface. 

 The manner in which many independent 

 factors are thus correlated is really of dra- 

 matic interest. 



SOUTH CAEOLINA. 



L. C. Glenn describes the physical fea- 

 tures of South Carolina (Journ. School 

 Geogr., IL, 1898, 9-15, 85-92), giving a 

 clear picture of the piedmont plateau 

 and the coastal plain. The piedmont is 

 a peneplain gently rolling over most of 

 the surface, but much dissected by nar- 

 row and branching side valleys near the 

 main streams. About the headwaters 

 many rapids and falls interrupt the 

 streams ; farther down the valleys the 

 larger rivers have opened narrow ' bottoms,' 

 whose fertility has been much impaired by 

 wash from carelessly farmed hillsides. The 

 middle and outer parts of the plateau carry 

 a number of monadnocks, such as Ruff's, 

 Parson's, King's and other low mountains. 

 On the inner part of the plateau the resid- 

 ual mountains are higher and more numer- 

 ous, rising 1,000 to 1,500 feet above the 

 peneplain. The coastal plain is hilly along 

 its inner border, low and smooth over most 

 of its extent. Here the chief rivers have 

 broad swampy flood plains. The numerous 

 channels that divide the islands along the 

 coast are ascribed to the strong tides of the 

 Carolina bight. 



It may be noted in this connection that 

 the Journal of Geography, edited by Professor 

 R. E. Dodge, of Teachers College, New 

 York, has published a number of first-hand 



