FOREST TREES. 183 
White Willow, or Golden Willow, set two feet apart 
in the rows. The cultivation should be continued 
until the whole are growing vigorously. The Pop- 
lars or Willows are to be thinned as occasion requires. 
If the trees are planted as indicated in the accompa- 
nying diagram, the Spruces will be about nine feet 
apart; they will be evenly distributed, and will have 
room to grow to such a size as to be of some value 
for timber before it will be necessary to thin them. 
The stars show the position of the Norway Spruces, 
the dots of the intermediate planting. At this dis- 
tance six hundred and forty trees may be grown 
upon an acre. Deciduous trees, which throw out stiff 
horizontal branches, like the Silver Maple, should not 
be planted among evergreens, as they are likely to 
interfere with and injure their leading shoots. 
4, Abies Canadensis—Hemlock, Hemlock Spruce. 
Leaves, one-half of an inch long, flat, linear, obtuse, 
dark green above, glaucous beneath; cones, three- 
quarters of an inch long, oval with few scales; branch- 
lets slender, drooping. 
The Hemlock is natural to the British Provinces of 
North America and to the coldest parts of the United 
States. It is found from the Atlantic to the Pacific 
Ocean; and as far north as Hudson Bay. In Virginia 
and North Carolina it grows only on the most elevated 
