There are but two leaves in a cluster on these kinds of pines and we shall find that the sheath which incloses the base of the leaf-cluster is more conspicuous than in either the white or the pitch pine. Do the leaves persist in the Scotch and Austrian pines longer than they do in the others we have examined? Study the cones of these and other pines. [Illustration: _Fig. 238. Scotch pine. Half natural size._] The Scotch and Austrian pines are not native to this country, but are much grown for ornament. They can be found in almost any park and in many other places where ornamental trees are grown. THE NORWAY SPRUCE. The leaves of spruce trees are borne very differently from those of the pines. Instead of being in clusters of two or more, they are single and without a sheath at the base; neither are there scale-like bodies on the branches where the leaves are borne. Notice, too, that the leaves have a very short stem or petiole. The leaves of the Norway spruce are about one inch long, although the length varies more or less in different parts of the tree and in different trees. They are rather stiff and rigid and sharp-pointed. In a general way, the leaves are four-sided, though indistinctly so. It will be interesting to study the position which the leaves take on the branches. A hasty glance might give us the impression that the leaves are not produced on the under side of the branches; but a more careful examination will convince us that there are nearly as many on the under side as on the upper. The leaves are all pointing outward from the branch and as nearly upward as is possible. In other words, the leaves grow toward the light. [Illustration: _Fig. 239. Austrian pine. One-third natural size._] We must not forget to see how long the leaves of the Norway spruce persist and to find out when the leaf-scars disappear. We can find leaves that must surely be six or seven years old and sometimes we can find them even older than this. The leaf scars, too, remain a long time. The falling of the leaves is illustrated in Fig. 240. It shows the extremities of a limb which is eight years old. The part between the tip and A is last season's growth; between A and B it is two years old; and beyond B is a part that grew three seasons ago. The section beyond C is six years old; from C to D is seven years of age. The four years' growth of this limb not shown in the drawing was as densely covered with foliage as is the part shown in the upper figure; but there are not many leaves between C and D (seven years old) and none on the eight-year-old wood (except those on the branchlets, and these are younger). The cone of the Norway spruce is nearly as long as that of the white pine, but it is not so rough and coarse as the white pine cone is. The cones are usually borne on the tips of small branchlets, although occasionally one is borne in the manner shown in Fig. 241. The cones usually fall the first winter.