THE DEVELOPMENT OF THE FRUIT 



535 



There is no evidence to indicate any immediate influence of pollen 

 on the color of the resulting fruit, or any direct effect on its composition, 

 flavor, quality, shape, season of maturity or keeping quality. This 

 statement is borne out by a number of extensive cross and self pollination 

 experiments^^' ^^^ as well as by a theoretical consideration of the nature 

 of the tissues and processes involved in fruit setting and maturing. Of 

 course if in a series of pollination experiments some pollen is used on a 

 certain variety and normal seed-containing fruits result and then pollen 

 of some other kind is used on other flowers stimulating them to set and 

 mature seedless fruit, differences in size, shape, composition and season of 

 maturity may be obtained. However, these are diversities associated 

 more directly with the relationship existing between seed formation and 

 fruit development and not directly between kind of pollen and fruit 

 development. In the same way the pollination of pistils of a given 

 sort with pollen of half a dozen other varieties with which it is inter- 

 fruitful may result in one crossing in fruits averaging say two seeds, in 

 another crossing in fruits averaging four seeds, and so on. Under these 

 conditions minor differences in size, composition, shape and even flesh 

 color and season of maturity may follow. Differences of this kind 

 probably account for such inequalities in fruit size in the pear as were 

 found by Waite^^^ when he used pollen of several kinds on Bartlett or 

 Kieffer pistils (see Table 10). 



Table 10. — Influence of Kind of Pollen on Fruit Size and Seed Weight 



IN Pears 

 {After Waite "2) 



The limited data available indicate that these variations are relatively 

 unimportant except in comparing cross pollinations with self pollinations. 

 That is to say, many varieties that will set and mature fruit when self 

 pollinated will set and mature distinctly larger fruits when cross pollinated, 

 regardless of the kind of pollen used if only it is from a compatible variety. 

 The explanation of the smaller fruits resulting from self pollination 

 is that though selfing often results in fruitf ulness the fruits bear few or no 

 perfect seeds, while the cross pollinated fruits have the usual number of 



