358 



Plant Physiology 



percentage of the flowers may have completed their 

 functions. According to Waite, apples in good season set 

 m no more than 5 per 



cent of fruit, and 

 of this small per- 

 centage much is 

 lost during fruit 

 development. If 

 we put this into 

 figures, we find 

 that 1000 apple 

 blossoms may 

 yield about 50 

 young fruits, of 

 which only some 

 few reach matu- 

 rity. In other 

 cases, practically 

 every ovule may 

 mature, if fertili- 



FIG. 101. Blossoms of cotton ; showy, but often zation is effected, 

 self-pollinated. ,,, . . ,. 



This is particu- 

 larly true of plants producing fewer flowers or floral axes, 

 as the corn or strawberry. 



208. Cross-fertilization and self-fertilization. - These 

 terms are used more or less loosely. Cross-fertilization 

 generally indicates a fusion of gametes derived from differ- 

 ent individuals, resulting, therefore, from pollination of a 

 stigma with pollen derived from a different plant. To be 

 consistent, self-fertilization would then indicate that both 

 gametes are derived from the same individual. 



