(40) 



in diameter, but in the Rocky Mountains it is seldom one- 

 half this size, and trees taken from the far northwest do not 

 thrive well on the Atlantic coast, owing to the much greater 

 rainfall which they naturally receive there ; the cones of the 

 Douglas spruce are from 2 to 4 inches long, pendant on the 

 branches, their scales rounded and shorter than the bracts 

 which project beyond them. 



The Hemlock Spruces {Tsuga) are planted between the 

 approach to the elevated railway station and the power 

 house, and are represented by the Canadian hemlock spruce 

 {Tsuga canadensis), the same species which forms the inter- 

 esting forest on the hills bordering the Bronx River within the 

 Garden, and indicated on the general plan as the hemlock 

 grove. This tree occasionally becomes about 90 feet high, 

 with a trunk up to 12 feet in diameter, and is distributed 

 throughout northeastern North America, extending south- 

 ward along the mountains to Alabama, northward to Nova 

 Scotia and westward to Minnesota. Its bark is the most 

 important tanning substance in the United States and a great 

 many trees are annually felled to obtain it ; its wood furnishes 

 a cheap lumber of little strength and durability. The Caro- 

 lina hemlock {Tsuga caroliniana), from the mountains of 

 southern Virginia to Georgia, may also be seen here, as well 

 as the Japanese hemlock spruce, to which the name Tsuga 

 was first applied. 



In the area to the westward of the conservatories, and 

 bounded by the surrounding paths, are the firs {Abies). 

 These can at once be distinguished from the spruces {Picea) 

 by the erect, instead of pendulous, cones, and by the smooth 

 branchlets. The wood of the firs is usually soft and not 

 durable, so it makes poor lumber. Specimens of the balsam 

 fir will be found here ; this is widely distributed over north- 

 ern North America, and from it is obtained Canada balsam 

 or balm of fir, used in the arts and in medicine. The Japan- 

 ese silver fir is an attractive plant, with its dark green stiff 

 foliage. Veitch's silver fir, from Japan, and said also to 

 occur on the neighboring coast of Manchuria, is one of the 



