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the Red River,” “ Principal Grasses in the Basin of the Red 
River,” ‘“ Maritime Plants in the Basin of the Red River,” and 
“Principal Weeds, Indigenous and Naturalized, in the Basin of 
the Red River.” The influence of the Ice Age upon the distri- 
bution of plants is discussed, and in reference to the region in 
question the author says: ‘‘ The.entire basin of the Red River 
of the North was covered by the ice-sheet, which also extended 
south to Saint Louis, and southwestward beyond the Missouri 
River, at the time of its maximum area in the early part of the 
Glacial Period, and to Des Moines, Yankton, the Coteau du Mis- 
souri, and the Elbow of the South Saskatchewan, at the time of 
its later great incursion. * * * Arctic and boreal plants were 
driven south during these epochs, to the central part of the 
United States, and at the close of the Ice Age they followed the 
receding ice-sheet and again took possession of the great northern 
region from which they had been expelled. With the restoration 
of a temperate climate throughout the northern United States 
and southern Canada, the arctic species found themselves no 
longer able to survive there, excepting in the cool heights of 
mountains, notably the White Mountains and the Adirondacks, 
and, in the case of a few species, on the cool, high northern 
shores of Lake Superior, and in the adjacent Isle Royal.” 
a HH. 
Geological Position of the Catskill Group—The. Charles S. 
Prosser. (Reprint from Amer. Geol., June, 1891). 
The author discusses the probable geological - position of the 
Catskill Group, making special use of the palzo-botanical evi- 
dence. A list of thirteen fossil plants is given from the New 
York and Pennsylvania areas, and another of nineteen species 
from Perry, Maine. 
Growth Periodicity of the Potato Tuber—On the. Conway 
Macmillan. (Am. Nat. xxv. 462-469. Also reprinted). 
Gymnosporangium (Cedar Apples)—The Connecticut Species of. 
Roland Thaxter. (Bull. No. 107, Conn. Agric. Exp. aoe 
New Haven, Conn., April 15th, 1891). 
The following species are described and their host plant noted: 
Gymnosporangium Ellisii, G. clavipes, G. conicum, G. mac- 
ropus, G. globosum, G. biseptatum, G. clavarieforme, and G. 
