Improving Plants and Seeds 141 



favorable conditions are thought to produce a more 

 variable offspring than wild or uncultivated plants. 



(b) By Hybridizing Dissimilar Forms, such as dif- 

 ferent varieties, or species. Many valuable varieties of 

 fruits have been secured by cross-fertilizing individuals 

 belonging to two different species. 



We have already noticed the variations in hybrid 

 blackberries (K 192). As a rule, the more dissimilar the 

 parents, the greater are the variations in the seedlings. 

 In choosing parents for hybrids, it is well to consider the 

 characters of each; for it is possible, though often quite 

 difficult, to combine the good qualities of two forms in 

 a single individual. 



210. Some Notable Results. Professor Munson found 

 that the varieties of the wine grapes, grown with such 

 success in Europe, and the fox grapes, in the eastern 

 United States, were not suited to the climate of the 

 Southwest. He sought to combine the hardiness of the 

 native wild grapes of Texas with the fine flavor and 

 fruitfulness of the foreign species by hybridizing. Many 

 valuable varieties of grapes well suited to Texas con- 

 ditions have been produced in this way. Some of the 

 most popular are the Carman, Fern, Muench, and 

 America, each having one-half of the native Post-oak 

 grape blood. The Kieffer pear is a hybrid between the 

 Bartlett and Chinese Sand pears. The Bartlett pear has 

 a delightful flavor but often suffers from blight. The 

 Sand pears are poor in flavor but quite hardy and fruit- 

 ful. Many fine varieties of plums, blackberries and dew- 

 berries have been produced by hybridization. 



211. Hybridization is accomplished by placing the 

 pollen of one variety or species upon the stigma of 

 another. To prevent self-pollination, the anthers should 



