Periodical Literature. 491 



Of nut trees, Juglans nigra, cinerea and Carya alba are said 

 to be useful only in protected situations on account of frost 

 danger. Hickory 20 years old is 16 feet, Walnut 10 years old, 7 

 feet No special advantages are attached to the American maples, 

 except perhaps the Sugar Maple. 



The American Ash is said to recover from overflow more 

 readily and resist late frosts better than the German. Curiously 

 enough our Black Cherry is supposed to be outranked in value by 

 the native cherries, evidently a misconception. 



Of conifers, next to Pinus Strobus, which is considered almost 

 a native, the palm is given to the Douglas Fir. Much distinction 

 is made between the green (from the Pacific Coast), the slow 

 gray glauca from the dry (Rockies) and the rapid gray variety 

 caesia (from the transition zone) The species is found not 

 adapted to dry and to heavy clay soils, indeed, makes consider- 

 able demand on both soil and air humidity. It recovers remark- 

 ably from attacks of Schiitte, a lo-year Douglas Fir, entirely de- 

 foliated by the disease recovering entirely. 



Picea pungens, the species of our driest mountain slopes, is 

 found successful in boggy situations where P. sitchensis had 

 failed, and is generally hardy, but requires patience as it grows 

 slowly (3 feet in 8 years). Its seed comes often mixed with P. 

 engelmanni. 



Picea alba is outgrown by the native spruce. With 18 years 

 the latter is 16 feet against 13 feet for the former; besides it 

 suffers from late frost, and is no better on moor soils than the 

 native. 



Pinus Banksiana is greatly preferred to rigida, especially on 

 poorest sands and on wet cold, higher elevations, where it does 

 better than the native silvestris. 



Of firs, Abies concolor is declared the most desirable introduc- 

 tion, growing more rapidly than the native pcctinata both in plain 

 and mountains. It does not stand wet feet, especially not wet- 

 cold clay soils. Seven year old plantations average 4 feet in 

 height, with leaders of 10 inches. Abies Nordmanniana, while 

 less liable to frost than the native fir, is much slower (20 inches 

 in 6 years, 13 feet in 21 years, etc.). 



Chamaecyparis Lazusoniana adapted to sand soils and loess, 

 but not to frost holes and wet-cold clay, at first slow, soon ac- 



