. Annual report of the Board of Regents of the Smithsonian Institution. Smithsonian Institution; Smithsonian Institution. Archives; Discoveries in science. BEES AND 475 Figure 3 shows the delnils of an oi'chid : Tlu' arcal lip (7) of the coroHa ends in a h)n(>), which are joined by the stipes (r) to a glutinous body (fr) at the entrance of the spur. Except the Oplii'ijs a pi f ('!?((, which, thaidvs to a si)ecial stnictuiv, can do so, the plants of this family are utterly inca|)able of self fei'tili/atiou. Nor can the wind aid them. The pollen gi-ains can easily be lifted up with
. Annual report of the Board of Regents of the Smithsonian Institution. Smithsonian Institution; Smithsonian Institution. Archives; Discoveries in science. BEES AND 475 Figure 3 shows the delnils of an oi'chid : Tlu' arcal lip (7) of the coroHa ends in a h)n(>), which are joined by the stipes (r) to a glutinous body (fr) at the entrance of the spur. Except the Oplii'ijs a pi f ('!?((, which, thaidvs to a si)ecial stnictuiv, can do so, the plants of this family are utterly inca|)able of self fei'tili/atiou. Nor can the wind aid them. The pollen gi-ains can easily be lifted up with a needle oi' })encil i)oint from the glutinous mass where they are collected. Tt is by an analagous process that honey bees effect the cross-fei'tilization of these jdants. On entering the sjjur in search of nectar they come into contact with the viscous disk (A) and generalh' cai-ry off one or two of the pollen grains attached somewhere (»n the front i)ortion of their body. As Darwin has shown, the sticky substance dries very quickly and when the insect 1 „ 2. Fl(i. 4.—Trauspiirtation of orcbi<I polloii luassos r)y bocs. iPoUpii ropreseiitfd )iy diaKHiial lines.) 1. FAllenia <liwi<1iiit<i. 3. Eualnsxa rnrdiilci. enters the spur of another flower the mass is abandoned so that it becomes attached to the stigma, where it yields the fertilizing element. The part that the insects play and the advantages of cross-fertiliza- tion among the orchids are shown with all possible clearness in the case of the vanilla. In Mexico this plant is fertilized naturally bv different insects, especially by the Melipones, which greatly resemble our bees, but in other regions artificial fertilization is produced by rubl)ing the stamen on the pistil with a needle. INI. Tjecomte. who has studied the matter, attributes the superior (pudity of the Mexican vanilla to the advantage of natiii'al cr()ss-fer(ilization over artificial auto-fertilization. In our own grwnhouses the vanilla plant
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