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. 



G 



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 they 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; , 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. All the vanilla beans in the Seychelles 

 Islands are grown with hand pollenation 



