16. =The Flower= of Flax consists, first, of five small green leaves, crowded into a circle: this is the CALYX, or flower-cup. When its separate leaves are referred to they are called SEPALS, a name which distinguishes them from foliage-leaves on the one hand, and from petals on the other. Then come five delicate and _colored_ leaves (in the Flax, blue), which form the COROLLA, and its leaves are PETALS; then a circle of organs, in which all likeness to leaves is lost, consisting of slender stalks with a knob at summit, the STAMENS; and lastly, in the centre, the rounded body, which becomes a pod, surmounted by five slender or stalk-like bodies. This, all together, is the PISTIL. The lower part of it, which is to contain the seeds, is the OVARY; the slender organs surmounting this are STYLES; the knob borne on the apex of each style is a STIGMA. Going back to the stamens, these are of two parts, viz. the stalk, called FILAMENT, and the body it bears, the ANTHER. Anthers are filled with POLLEN, a powdery substance made up of minute grains. 17. The pollen shed from the anthers when they open falls upon or is conveyed to the stigmas; then the pollen-grains set up a kind of growth (to be discerned only by aid of a good microscope), which penetrates the style: this growth takes the form of a thread more delicate than the finest spider's web, and reaches the bodies which are to become seeds (OVULES they are called until this change occurs); these, touched by this influence, are incited to a new growth within, which becomes an embryo. So, as the ovary ripens into the seed-pod or capsule (Fig. 1, etc.) containing seeds, each seed enclosing a rudimentary new plantlet, the round of this vegetable existence is completed. Section III. MORPHOLOGY OF SEEDLINGS. 18. Having obtained a general idea of the growth and parts of a phanerogamous plant from the common Flax of the field, the seeds and seedlings of other familiar plants may be taken up, and their variations from the assumed pattern examined. 19. =Germinating Maples= are excellent to begin with, the parts being so much larger than in Flax that a common magnifying glass, although convenient, is hardly necessary. The only disadvantage is that fresh seeds are not readily to be had at all seasons. [Illustration: Fig. 11. Embryo of Sugar Maple, cut through lengthwise and taken out of the seed. 12, 13. Whole embryo of same just beginning to grow; _a_, the stemlet or caulicle, which in 13 has considerably lengthened.] 20. The seeds of Sugar Maple ripen at the end of summer, and germinate in early spring. The embryo fills the whole seed, in which it is nicely packed; and the nature of the parts is obvious even before growth begins. There is a stemlet (caulicle) and a pair of long and narrow seed-leaves (cotyledons), doubled up and coiled, green even in the seed, and in germination at once unfolding into the first pair of foliage-leaves, though of shape quite unlike those that follow.