SEX AND FERTILIZATION. 101 



an occasion to interfere with the natural processes of re- 

 production, {n a state of nature, the sexes are gener- 

 ally placed in positions favorable to direct intercourse, 

 either by contact, or through natural vehicles, for the 

 transmission of pollen from the male to the female organs. 

 If the sexes are widely separated on different plants, or 

 on different parts of the same plant, wind and insects, 

 either or both, become the n^edia for transporting pollen, 

 and every person who is at all observing, and takes an 

 interest in such matters, must not only have noticed the 

 clouds of yellow dust blown from Pine, Chestnut, and 

 similar kinds of trees, but also the pollen-laden bees and 

 other insects that pass from flower to flower, in search of 

 honey or whatever may serve them for food and other 

 purposes. 



While in the larger majority of plants both anthers 

 and pollen-grains are of a yellow or yellowish-white 

 color, still there are many exceptions, and red, brown, 

 blue and other shades of color are seen in the pollen even 

 among the plants of the same family or genus. 



In some plants there appears to be considerable 

 mechanical force required for the proper distribution of 

 the pollen; this is exhibited in a peculiar manner in the na- 

 tive Kalmias. In these plants the stamens are so arranged 

 that they are bent back with the expansion of the flower, 

 and held in this position for several days, and when re- 

 lieved by the petals they spring back to the center, strik- 

 ing the stigma with considerable force, the anther cells 

 bursting at the same time and widely scattering the 

 pollen. The position and form of the stamens in the 

 flower of the Kalmia are shown, greatly magnified, in 

 figure 43. In some the female organs are shorter and 

 placed below the male, the pollen dropping from the 

 anthers upon the stigmas; or in drooping flowers, like the 

 Fuchsia, the pistils may be many times longer than the 

 stamens, but if extending below them they receive the 



