BRANCHES AND LEAVES IN CONIFERA. 657 
Pinus sylvestris in their foliation, habits, and locality, that we cannot for a 
moment hesitate about their connection with that species.”—P. 956. 
These researches, on the other hand, seem to show that the alliance of these 
species is with Pinus austriaca. Instead of retaining on their branches during 
winter only two years’ growth of leaves, like the Scotch Fir, they retain four 
years’ growth, like the black Austrian. Moreover, they have the same spread- 
ing habit as the Austrian Pine, throwing out limbs nearly as heavy as the main 
stem. They have, besides, another very striking character in common with the 
Austrian Pine, in the young shoots in spring being clothed with conspicuous 
white silky bud-scales, very unlike the dull greenish brown ones clothing the 
young shoots of the Scotch Fir. 
In consequence of the high elevation of my property above the sea, viz., 900 
feet, and the consequent destruction of all the more tender pines by spring 
frosts, I have not had an opportunity of studying with sufficient minuteness 
the defoliation of the more recently introduced species of the genus Pinus; but 
other observers will easily supply the deficiency. 
Abies (Spruce Fir), Picea (Silver Fir).*—These genera differ widely from the 
Pines in that they retain their leaves so long on the branches that the exact 
number of years which elapse before they are thrown off cannot be accurately 
ascertained. Moreover, they exhibit defoliation properly so called, as distin-- 
guished from the cladopiosis of the Pines and Cypresses, the leaves being shed 
singly. In most of the trees, leaves are dropping off all summer; but a far 
higher proportion are cast off during November than any other month of the 
year. On healthy free-growing trees I have often counted from seven to nine 
annual growths still thickly covered with leaves, so that from seven to nine 
years may elapse before the leaves drop from these trees. On very old trees, 
however, the leaves seem to be cast off after having been only five years on 
the tree, and chiefly during the month of November. 
In Araucaria imbricata, the leaves do not seem to be united to the stem by 
an articulation. From this circumstance it does not shed its leaves, which 
seem only to be destroyed through the increasing diameter of the stem, and 
the increasing thickness of the bark probably impairing their vitality. 
Larix europea (Common Larch).—This, like all species of the genus, is a 
deciduous tree; the leaves developed in spring being thrown off in November. 
The Larch has two kinds of shoots; one consisting of actively elongating 
branches with the leaves solitary and scattered in a loose spiral; the other 
consisting of shortened stunted branches, with undeveloped internodes, so that 
the leaves come to be crowded in bundles or fascicles. The stunted branches 
producing the leaf-fascicles I shall term spurs. 
* The Continental botanists transpose these gencric names. 
