384 Bulletin 181. 



Figs. 82-86. In some varieties the difference was very marked, as 

 witli Stark and Longfield apples (Fig. 82-83) ; in others the differ- 

 ence was not so marked, as Abundance (Fig. 81:) ; while a few showed 

 no appreciable increase in size from cross-pollination, as Talman 

 Sweet and Bradshaw (Fig. 85-86). The difference between the 

 cross and self-pollinated Starks and Longiields is so striking that one 

 wonld almost be tempted to think the self-pollinated fruits were 

 wormy, but they were not. The self-pollinated Talmans and Brad- 

 shaws were apparently as fine in every way as the cross-pollinated 

 frnits. Manning Elizabeth pear also was not benefited by pollen 

 from other varieties. 



The throe self-pollinated Longfields here shown (Fig. 83) had but 

 five sound seeds; while the two crossed specimens had seventeen 

 sound seeds. In general, cross-pollinated, fruits have more good 

 seeds than self pollinated fruits, but there is no constant relation 

 between the size of a fruit and the number of seeds it contains. 

 Some of the biggest apples or pears may have only two or three 

 good seeds. In case the ovules in one cell of an apple or pear core 

 are not fertilized, that part of the fruit adjoining is often stunted 

 and the fruit becomes lop-sided in consequence ; but this, likewise, 

 does not always follow. 



All of the above varieties are self -fertile, at least in Ithaca. They 

 will produce fruit with their own pollen. But we have seen that 

 some of them will produce better fruit if other pollen is supplied. 

 Is it not worth while, then, to plant pollinizers even with self-fertile 

 varieties — that is, to practice mixed planting with all varieties? 

 There are three good reasons for doing this : First, some believe 

 that self-sterility is likely to increase in the future, under the stimu- 

 lus of high cultivation. Second, we can never be perfectly sure 

 that any variety will be self-fertile on our soil and under our cul- 

 ture ; even those varieties which are self-fertile elsewhere may be 

 partially self-sterile with us. Third, most self-fertile as well as self- 

 sterile varieties are benefited by cross-pollination. It is taking risks 

 to plant a very large block of one variety. The trees may bear just 

 as much and just as fine fruit as though other varieties were with 

 them, but the chances are against it. 



