1. _Action of the Parent._--The Ivy-leaved Toad-flax, or Mother-of-Thousands (_Linaria Cymbalaria_), is a pretty little plant, native in central and southern Europe, naturalized and common on old walls in this country. Its Snapdragon-shaped purple flowers are borne on short stalks which curve towards the light, placing the blossoms in a conspicuous position, where they may be the more readily visited by insects, and thus pollinated. But when flowering is over, and the little round fruit is ripening, the stalk twists so that the fruit is turned towards the wall and finally pushed into any convenient crevice: when the capsule opens, the seeds, instead of dropping to the base of the wall where on germination the young plants would be smothered among stronger growths, find themselves lodged in niches in which the young plants may develop successfully. Many water plants have flowers which rise into the air, following on which the flower-stem curves and the seed is ripened below the surface, free from the dangers of weather, of feeding water birds, and so on. A very common type is that in which the seed-vessel opens at the top when the seed is mature. Gusts of wind, or passing animals, bending the stem, cause the latter to spring back, casting the seeds out. When the seed-vessel opens widely, as in the Columbine (_Aquilegia_), the seeds may be cast to some small distance. The efficacy of the arrangement is not so obvious when, as in the Poppies (_Papaver_) or Bell-flowers (_Campanula_), the openings are small (Fig. 8), but it is clear that these plants do not suffer from lack of dispersal, in view of their abundance and wide range. [Illustration: FIG. 8.--FRUIT OF GIANT BELL-FLOWER (CAMPANULA LATIFOLIA). 3/4.]