88 VEGETABLE GARDENING 



with a special object in view, will convince the most skep- 

 tical of the wonderful power which man possesses to adapt 

 plants to his needs. 



Cross- and Self-pollination of Plants. The flowers of 

 plants are said to be either self-pollinized or cross-pollinized. 

 By self-pollination is meant the pollination of the female 

 organ (pistil) by the male element (pollen) of the same 

 flower or, in some cases, of different flowers of the same 

 plant, as in corn and squashes, which have two kinds of 

 flowers. By crossing or cross-pollination is meant the pol- 

 lination of the female organ by pollen from another plant. 

 The crossing of different varieties generally gives increased 

 vigor in the progeny, but its effect is variable and may re- 

 sult in the loss as well as in the increase of their desirable 

 qualities. Most of our cultivated plants are crossed by 

 natural processes. The crossing of different seed stocks of 

 the same varieties of plants is generally a great advantage, 

 since it generally results in increased vigor without loss of 

 desirable qualities. Seeds from self-pollinized flowers are 

 not as productive as crossed flowers. Darwin found that 

 cabbage plants from seeds that had been crossed produced 

 nearly three times the weight produced by self-pollinized 

 seeds. 



In the case of Indian corn, experiments made at the 

 Illinois experiment station show that while cross-fertiliza- 

 tion is not necessary, it is very desirable. Corn grown 

 from crossed seed in -nearly all cases was clearly increased 

 in size as the result of crossing. "Plants grown from self- 

 fertilized seed corn were in most cases notably inferior in 

 size and vigor to the plants grown from hand-crossed seed 

 or from seed simply selected which was probably naturally 

 crossed. One plat from self-fertilized seed had nearly 

 half the stalks deformed in such a manner that instead of 



