534 EVERGREEN TREES AND SHRUBS. 
shoot is three or four feet long, and extremely succulent, this rup- 
ture is most often the result when the sun being hot, activity of 
circulation is excessive. When, however, the exuberance of 
growth is checked by poor, thin soil, the tree grows enough, 
and seems to mature its wood — at any rate sufficient to with- 
stand what might be called determination of sap to the head ; 
so that, in future, we shall always plant excelsas in poor soil.” 
It is some years since the above was written. Mr. Sargent’s 
finest trees of this species are now in a precarious condition. He 
has stated the symptoms of their decline, but there seems to be 
something in the inherent organism of the tree to produce these 
results, which will not be fully counteracted by the treatment 
recommended. The fact that Parsons & Co.’s superb tree — 
probably the finest in this country — is growing healthily (thus far) 
in a soil rich enough to produce the most luxuriant growth, tends to 
prove that the rank growth is not the invariable cause of the decay 
of these trees. This tree is growing in a position exposed on all 
sides to wind and sun. We have seen the commonly cultivated 
varieties of cherry, like the black tartarian and the yellow Spanish, 
growing in different soils in the same town ; in one, always forming 
short well-ripened wood, and growing into healthy trees; and in 
the other, growing excessively, and developing early disease and 
decay. A well-drained stiff clay produces the healthy trees ; and 
a warm sandy surface soil, with a springy subsoil, produces a 
plethora of growth, rupture of the bark, exudation of gum, and 
all the symptoms of a diseased condition. If a tree that succeeds 
so generally in the northern States as the cherry, is liable to the 
peculiar form of disease that distinguishes the Bhotan pine, it is a 
reason to be hopeful that the best soil and exposure for the latter 
may be determined, so as to give assurance of growing it to maturity 
in some localities. We would follow Mr. Sargent’s suggestions 
implicitly as far as relates to starting the tree in a poor surface 
soil, . but we would leave it exposed on all sides to the sun and 
wind from the beginning, and seek to harden its growth by giving it 
deep I'oot in a rich dry subsoil. 
But it must be remembered that the Bhotan pine is a native of 
the latitude of the northern shore of the Gulf of Mexico ; and it is 
