=854. Pollination of jack-in-the-pulpit.=—The jack-in-the-pulpit (Arisæma triphyllum) has made greater advance in the art of enforcing cross pollination. The larger number of plants here are, as we have found, diœcious, the staminate flowers being on the spadix of one plant, while the pistillate flowers are on the spadix of another. In a few plants, however, we find both female and male flowers on the same spadix. =855.= The pretty bell-flower (Campanula rotundifolia) is dichogamous and proterandrous (fig. 462). Many of the composites are also dichogamous. =856. Pollination of orchids.=—But some of the most marvellous adaptations for cross pollination by insects are found in the orchids, or members of the orchis family. The larger number of the members of this family grow in the tropics. Many of these in the forests are supported in lofty trees where they are brought near the sunlight, and such are called “epiphytes.” A number of species of orchids are distributed in temperate regions. [Illustration: Fig. 461. A group of jacks.] =857. Cypripedium, or lady-slipper.=—One species of the lady-slipper is shown in fig. 468. The labellum in this genus is shaped like a shoe, as one can see by the section of the flower in fig. 468. The stigma is situated at _st_, while the anther is situated at _a_, upon the style. The insect enters about the middle of the boat-shaped labellum. In going out it passes up and out at the end near the flower stalk. In doing this it passes the stigma first and the anther last, rubbing against both. The pollen caught on the head of the insect, will not touch the stigma of the same flower, but will be in position to come in contact with the stigma of the next flower visited. [Illustration: Fig. 462. Proterandry in the bell-flower (campanula). Left figure shows the syngenœcious stamens surrounding the immature style and stigma. Middle figure shows the immature stigma being pushed through the tube and brushing out the pollen; while in the right-hand figure, after the pollen has disappeared, the lobes of the stigma open out to receive pollen from another flower.] =858. Epipactis.=—In epipactis, shown in fig. 469, the action is similar to that of the blue iris. [Illustration: Fig. 463. Kalmia latifolia, showing position of anthers before insect visits, and at the right the scattering of the pollen when disturbed by insects. Middle figure section of flower.]