THE FLOAVERS AXD FRUITS. 35 



35. Perfect and Imperfect Flowers. — Where the stamens 

 and pistils are found in the same flower it is called perfect 

 or hermaphrodite, as in most of our orchard fruits and 

 garden plants. But when only one sex of these essential 

 organs is found in the same flower it is called imperfect. 

 This with the fruits is often caused by cultivation or 

 crossing, as in the strawberry, where some varieties have 

 perfect and others imperfect flowers. Some of the hybrid 

 grapes and other fruits are practically imperfect. Though 

 they show imperfect stamens, they are not capable of self- 

 pollination. In still other cases the stamens and pistils 

 do not develop together. In some pears, cherries, and 

 plums the pistils are erect and show receptive stigmas 

 while the stamens are yet undeveloped. In such cases 

 cross pollination of varieties is essential to fruitage. 



36. Cross-pollination. — Even when the flowers seem 

 perfect in all respects they often in the cultivated fruits 

 seem incapable of self-pollination. This is not confined 

 to the individual flower or to the flowers of a single tree 

 or a large block of trees. As a rule, large blocks of a 

 single variety of the orchard fruits have not proven pro- 

 ductive. As Bailey says : " "We chiefly know that the most 

 productive orchards are usually those of many varieties, 

 and that some varieties sometimes refuse to fertilize them- 

 selves." The concensus of opinion at this time of those 

 with most experience and extended observation is that it 

 is best to mingle varieties of the cultivated fruits and nuts 

 in planting for profit or home use. 



37. Nutrition of the Fruit-blossom. — Growers of the 

 strawberry now unite mainly in the belief that the flowers 

 of the pistillate varieties are capable of enduring unharmed 

 frosts and adverse weather conditions that destroy the 

 germs of perfect varieties. The reason given is that 

 pollen-bearing is an exhausting process. As the pistillate 



