Elementary botany . e of fertilization. this time the ovule has exuded a drop of a sticky fluid in thisdepression between the curved processes at its lower end. Thepollen sticks to this, and later, as this viscid substance dries up,it pulls the pollen close up in the depression against the lower 304 M0RPH0L0G V. end of the ovule. This depression is thus known as the pollen chamber. 618. Now the open scales on the young female cone close up again so tightly that water from rains is excluded. What is alsovery curious, the cones, which up to thistime have been standing erect, so thatthe open scal
Elementary botany . e of fertilization. this time the ovule has exuded a drop of a sticky fluid in thisdepression between the curved processes at its lower end. Thepollen sticks to this, and later, as this viscid substance dries up,it pulls the pollen close up in the depression against the lower 304 M0RPH0L0G V. end of the ovule. This depression is thus known as the pollen chamber. 618. Now the open scales on the young female cone close up again so tightly that water from rains is excluded. What is alsovery curious, the cones, which up to thistime have been standing erect, so thatthe open scale could catch the pollen,now turn so that they hang more certainly excludes the rains,since the overlapping of the scales formsa shingled surface. Quantities of resinare also formed in the scales, whichexudes and makes the cone practicallyimpervious to water. 619. The female cone now slowlygrows during the summer and autumn,increasing but little in size during thistime. During the winter it rests, that. Pig- 35 of pine(ovule), int, integument; n, ^JhSbSTTj&fi is>ceases t0 §row- With the coming of fjongy tfssuTle(Srer f£- spring, growth commences again andguson) at an accelerated rate. The increase in size is more rapid. The cone reaches maturity in thus see that nearly eighteen months elapse from the begin-ning of the female flower to the maturity of the cone, and aboutfifteen months from the time that pollination takes place. 620. Female prothallium of the pine.—To study this we must make care-ful longitudinal sections through the ovule (better made with the aid of amicrotome). Such a section is shown in fig. 358. The outer layer of tis-sue, which at the upper end (point where the scale is attached to the axis ofthe cone) stands free, is the ovular coat, or integument. Within this integu-ment, near the upper end, there is a cone-shaped mass of tissue. Thismass of tissue is the nucellus, or the macrosporangium proper. In thelo
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