The plants of this order exhibit a number of interesting adaptations in their natural history. The Composita. are generally considered as the highest expression of development in the plant world, and they exhibit a number of modifica tions by \\Ilia they have become the most nu merous and aggressive of all plants. In many genera the gradations between species are so con fusing as to make their proper classification well nigh impossible. The distribution of the fruit has been about by many special modifica tions. In the dandelion, thistle, and others, the calyx develops, after the fertilization of the flower, into a plunmse pappus by which the fruits are scattered by the winds. In the tiekseed and bur-marigold the aehenes are crowned with sev eral barbed awns that catch in the hairs of ani mals and the clothing of man, aiding materially in their wide dissemination. In the burdock and cockle-bur the involnere is furnished with curved honks which serve to aid in the dispersal of these plants. Other seeds, such as those of the Madia, the tarweeds, are covered, especially upon their involucres, with a very thick adhesive exudation that adheres to anything with which the seeds conic. in contact. and these are carried away often to great distances.
The means devised for the fertilization of the flowers is admirably adapted to seeure numerous progeny. The flower.; being small and crowded together, several can take advantage of the visit of a single insect laden with pollen. Some are
wind-pollenized, their close position aiding in it. The mechanism of the individual flower for pol lination is curiously pe•feet. When the flower opens. the style. with its stigmatic surfaces close ly pressed together. forces its way nut through the stamen-tube, carrying the' pollen out where it can tonne in contact with insect visitors or be blown away by the wind. At this time the flower is not ready for its own fertilization. When re ceptive, the style has protruded from the tube and the stigmas separate, curving backward. If they do not receive pollen from another flower to tints secure the desired cross-fertilization, they continue to curl backward until they come ill contact with the pollen, some of which still remains upon their own style, and they thus be come self-fertilized. In this way the setting of seed is assured to every flower. In conclusion, the remarkable success of this order may be at tributed to a number of factors, such as the massing of the flowers, resulting in greater con spicuousne:,, to attract insect visitors, one visit or fertilizing many flowers; a simple floral mech anism to protect and distribute the pollen, and the special devices described above to secure the dispersal of the seeds. See articles on various members of the order.