. Elementary biology; an introduction to the science of life. Biology. ADAPTATIONS OF FLOWERS 313 Instead of importing the insects to carry on pollenation, it was decided to hire women and children to go from flower to flower and pollenate by hand (see Fig. 142). In our regular horti- culture it happens occa- sionally that trees or bushes in full blossom fail to yield the expected crop of fruit because of the lack of insects to in- sure pollenation. This is why wise farmers and or- chardmen so often main- tain hives of bees in the neighborhood of their fields or orchards. Even where the honey
. Elementary biology; an introduction to the science of life. Biology. ADAPTATIONS OF FLOWERS 313 Instead of importing the insects to carry on pollenation, it was decided to hire women and children to go from flower to flower and pollenate by hand (see Fig. 142). In our regular horti- culture it happens occa- sionally that trees or bushes in full blossom fail to yield the expected crop of fruit because of the lack of insects to in- sure pollenation. This is why wise farmers and or- chardmen so often main- tain hives of bees in the neighborhood of their fields or orchards. Even where the honey is not worth getting, the bees are worth having because they insure abundant pol- lenation at the right time. Fig. 142. Hand-pollenation in the vanilla flower 368. Advantage of insect pollenation doubtful. In a general way the lower fam- ilies of seed plants are wind-pollenated, and the higher families are insect- pollenated. But it must not be supposed that there is any real advantage to plants in depending upon insects to carry their pollen. In many cases we may see that there is an actual saving of pollen. On the other hand, many species of plants, especially among the orchids, are so dependent upon the insect visits that thev are dying. In the orchids the stamens are fused with the stigma, placing the anthers above the stigma in such a way as to make self-pollenation absolutely im- possible, an, anther; /, pollen masses : s, stigma. A, general view of flower; B, position of hands and needle in artificial pollenation ; C, needle lift- ing pollen masses; D, anther raised to expose pollen masses ; E, style raised to show opening in stigma; F. longitudinal section to show relative positions of anther and stigma: G. longitudinal section after pollenation, showing pollen masses in the stigma. .\11 the vanilla beans in the Seychelles Islands are grown with hand pollenation. Please note that these images are extracted from scanned page images that may have been digitally enhanced f
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