144 MR. R. TRIMEN ON THE FERTILIZATION 
applied to many of the uses fulfilled by the Thuja gigantea (‘ Ce- 
dar’) on the other side of the Cascades, such as making shingles, 
rails for fences, &c. - 
Thuja gigantea, Nutt., which, as already mentioned, is common 
and grows to a very large size near the sea-coast, is comparatively 
scarce in the interior, where it is only met with in damp, shady 
ravines, or near moist river-banks such as those of the Pend 
Oreille ; but even there it seldom attains a size at all to be com- 
pared with that which it reaches on the western side of the 
Cascades. 
Juniperus Virginiana, L., occurs occasionally in the form of a 
tree in Vancouver Island, as well as along the boundary up to the 
Rocky Mountains. The measurements of one at Esquimalt were 
—circumference at six feet above the ground, 5 feet 4 inches; 
length of same tree (which had been blown down) 46 feet. Low- 
est branch five feet from the ground. 
Acer macrophyllum, Pursh, one of the ornamental trees of the 
western forests, was not observed to the eastward of the Cascade 
Range. 
Quercus Garryana, Doug. (the only Oak seen), which is plentiful 
at the S.E. end of Vancouver Island, was not found on the main- 
land anywhere along the 49th parallel. It was seen in the neigh- 
bourhood of the Dalles, but did not extend much higher on the 
Columbia. 
On the Fertilization of Disa grandiflora, Linn. By RorANDp 
Tart, Esq., of the Colonial Office, Cape Town: drawn up 
from Notes and Drawings sent to C. Darwry, Esq., F.L.S., &c. 
[Read June 4, 1863.] 
As none of the many various South African Orchids have been 
described in relation to their manner of fertilization, I have 
thought that a brief account of the structure of the Disa grandi- 
flora might be acceptable. 
In the great majority of Orchids the labellum, or lower lip, 
secretes nectar, and stands in front of the column which bears the 
stigma and pollen-masses. In the Disa the labellum is greatly 
reduced in size; the posterior sepal, on the other hand, is largely 
developed, and forms a spur which contains nectar. As the nec- 
tary thus stands at the back of the column (see fig. C) behind the 
stigma and pollen-masses, in a directly opposite position to that 
which it occupies in other Orchids, it may naturally be asked, 
