312 LUSSONS WITE PLANTS 



fail (296). There are five styles and stigmas in 

 the apple flower. If pollen is applied to two or 

 three of them only, the corresponding carpels will 

 develop and the remaining carpels will develop no 

 seeds. The part of the apple in which the seeds 

 are borne grows most rapidly and the apple be- 

 comes one-sided. If there are fewer pollen grains 

 applied to the stigma of any flower 

 than there are ovules in the ovary, 

 the normal number of seeds may 

 not form, and the fruit remains 

 comparatively small. If it happens 

 that the impregnated ovules are 

 One-sided tomato, ^ostly upon ouc side of ^ the 

 resulting from in- ovary the fruit bccomcs one-sided, 



sufficient pollen. ^^ .^ ^^^ ^^^^^^ ^j,.^_ g^^^^ ^j^ 



this shows that the development of the seed exerts 

 a great influence upon the development of the 

 fruit; and since the development of the seed is 

 dependent directly upon the pollen, it follows that 

 the pollen supply is a most important factor in 

 the production of large and symmetrical fruits. 



379. Plants of very unlike kinds will not often 

 inter -cross; yet it sometimes happens that after 

 inter- pollination between such plants, the fruit will 

 develop to considerable size, even though no seeds 

 form. It is also found, by experiment, that the 

 application of more pollen than is necessary for 



