We have thus seen adaptation to the thorax, the eyes, and the face in the three examples given. And the entrance of the flower in each instance is so formed as to insure the proper angle of approach for the insect for the accomplishment of the desired result. This direct approach, so necessary in many orchids, is insured by various devices--by the position of the lip upon which the insect must alight; by the narrowed entrance of the throat of the flower in front of the nectary; by a fissure in the centre of the lip, by which the tongue is conducted, etc. [Illustration: Fig. 10 C] Many other species allied to the above possess similar devices, with slight variations; and there is still another group whose structure is distinctly adjusted to the _tongues_ of insects--adaptations not merely of position of pollen masses, but even to the extent of a special modification in the entrance to the flower and the shape of the sticky gland, by which it may more securely adhere to that sipping member. In the common pretty Purple-fringed Orchid, whose dense cylindrical spikes of plumy blossoms occasionally empurple whole marshes, we have an arrangement quite similar to the _H. orbicularis_ just described, with the exception that the pollen-pouches are almost parallel, and not noticeably spread at the base (Fig. 11). In this case the eyes of sipping butterflies occasionally get their decoration of a tiny golden club, but more frequently their tongues. [Illustration: Fig. 11] If, however, the butterfly should approach directly in front of the flower, as in a larger blossom he would be most apt to do, he might sip the nectar indefinitely and withdraw his tongue without bringing it in contact with the viscid pollen discs. But in the dense crowding of the flowers, over which the insect flutters indiscriminately, the approach is oftenest made obliquely, and thus the tongue brushes the disc on the side approached, and the pollen mass is withdrawn. But an examination of this orchid affords no pronounced evidence of any specific intention. There is no unmistakable sign to demonstrate which approach is preferred or designed by the flower, and this dependence on the insect's tongue or eye would seem to be left to chance. In another closely allied species, however, we have a distinct provision which insures the proper approach of the tongue--one of many similar devices by which the tongue is conducted directly to one or the other of the pollen discs. [Illustration: Fig. 12]