14 PRINCIPLES OF THE GROWTH OF TREES. 



impregnated by the pollen of the anthers at the top, no grains 

 of corn will be produced. 



Sometimes the staminate and pistillate flowers are not only 

 separate, but are on distinct plants, as the Buckthorn and 

 Hemp. The pistillate flowers are 

 said to be fertile, and the staminate 

 sterile, and both must be planted 

 near each other in order to obtain 

 fruit or seed. 



Sometimes the stamens, when not 

 absent, are so defective that they 

 cannot fertilize the pistils, or but 

 imperfectly. This is the case with some of the pistillate 

 strawberries; such, for example, as Hovey's Seedling and the 

 Crescent. In order to produce good crops, some other vari- 

 ety that has perfect flowers or perfectly-developed stamens,- 

 as the Scarlet, or Wilson, must be planted near, from which the 

 wind may waft or the bees carry the pollen to the imperfect 

 flowers. Fig. 12 represents the flower of a staminate straw- 

 berry, or one in which stamens as well as pistils are perfect; 

 Fig. 13 is a pistillate flower, the stamens being small, and con- 



/-? 



FIG. 12. FIG. 13. 



Staminate Flower. Pistillate 

 Flower. 



FIG. 14. Stamens of Scarlet 

 Strawberry. 



FIG. 15. Stamens of Hovey's 

 Seedling. 



taining but little pollen in the anthers. Fig. 14 is an enlarged 

 view of the former, a being the stamens, and b the pistils. Fig. 

 15 is a flower of Hovey's Seedling showing at a the dwarfed 

 and useless stamens. Sometimes very favorable circumstances 

 will enable these dwarfs to afford a portion of pollen, and 

 berries will be produced. Some pistillate varieties are desti- 

 tute of stamens. 



SPECIES AND VARIETIES. 



Plants and animals of one species are supposed never to 

 produce a progeny of a different one, no matter how many 



