=613. Form of the mature female cone.=—A cluster of the white pine cones is shown in fig. 344. These are mature, and the scales have spread as they do when mature and becoming dry, in order that the seeds may be set at liberty. The general outline of the cone is lanceolate, or long oval, and somewhat curved. It measures about 10-15_cm_ long. If we remove one of the scales, just as they are beginning to spread, or before the seeds have scattered, we shall find the seeds attached to the upper surface at the lower end. There are two seeds on each scale, one at each lower angle. They are ovate in outline, and shaped somewhat like a biconvex lens. At this time the seeds easily fall away, and may be freed by jarring the cone. As the seed is detached from the scale a strip of tissue from the latter is peeled off. This forms a “wing” for the seed. It is attached to one end and is shaped something like a knife blade. On the back of the scale is a small appendage known as the cover scale. [Illustration: Fig. 346. Sterile scale. Seeds undeveloped.] [Illustration: Fig. 347. Scale with well-developed seeds.] [Illustration: Fig. 348. Seeds have split off from scale.] [Illustration: Fig. 349. Back of scale with small cover scale.] [Illustration: Fig. 350. Winged seed free from scale. Figs. 346-350.—White pine showing details of mature scales and seed.] [Illustration: Fig. 351. Female cones of the pine at time of pollination, about natural size.] =614. Formation of the female pine cone.=—The female flowers begin their development rather late in the spring of the year. They are formed from terminal buds of the higher branches of the tree. In this way the cone may terminate the main shoot of a branch, or of the lateral shoots in a whorl. After growth has proceeded for some time in the spring, the terminal portion begins to assume the appearance of a young female cone or flower. These young female cones, at about the time that the pollen is escaping from the anthers, are long ovate, measuring about 6-10 _mm_ long. They stand upright as shown in fig. 351. =615. Form of a “scale” of the female flower.=—If we remove one of the scales from the cone at this stage we can better study it in detail. It is flattened, and oval in outline, with a stout “rib,” if it may be so called, running through the middle line and terminating in a point. The scale is in two parts as shown in fig. 354, which is a view of the under side. The small “outgrowth” which appears as an appendage is the cover scale, for while it is smaller in the pine than the other portion, in some of the relatives of the pine it is larger than its mate, and being on the outside, covers it. (The inner scale is sometimes called the ovuliferous scale, because it bears the ovules.) [Illustration: Fig. 352. Section of female cone of white pine, showing young ovules (macrosporangia) at base of the ovuliferous scales.]