IMPROVEMENT OF CORN. 267 



selected one ; the pollen is carefully taken from the anthers 

 upon a soft camels hair brush, and is placed upon the re- 

 ceptive stigmas; the flower being then covered as before. 

 If the pollen is received the pistils soon begin to wither and 

 the ovaries swell ; showing that the ovules havelbeen fecun- 

 dated. 



There are other cases in which a still more careful opera- 

 tion is required. Some plants are self fertilizing, and can- 

 not be crossed with the pollen of other plants even natur- 

 ally. Wheat is such a plant; hence it is impossible for 

 varieties to change excepting by what is known as "sport- 

 ing." To cross wheats then, it is necessary to proceed as 

 follows. Before the flowers open and the anthers appear, 

 the glumes or coverings of the buds, which answer to the 

 calyx of other flowers, are carefully opened or removed; and 

 the organs of the flowers are exposed. The anthers are 

 then cut off as above mentioned, and the pistils are fertilized 

 with the chosen pollen communicated as before described. 

 The ear of the plant is then enveloped in a protecting cov- 

 ering of fine gauze, and the operation is complete. Most 

 important results have been reached in this way and the 

 field for experiment is boundless. 



In crossing corn all that is necessary is to grow some 

 plants in a plot by themselves; to remove the tassels as soon 

 as they appear; and to protect the silk by gauze coverings. 

 When the silk is in the right condition, the mature tassels 

 from the desired plants are shaken over the silks to scatter 

 the pollen upon them, by which the fertilization is effected. 

 This operation should be repeated daily until it is seen that 

 the silk has received and absorbed the pollen, which is 

 shown by its withering and drying up. 



In regard to the fertilizing of corn by the natural pro- 

 cess a very important point might here be mentioned. This 

 is the crossing by an imperfect plant. A perfect plant of 

 corn is one that has both kinds of flowers; that is, a tassel, 

 and an ear and silk. Such a plant is productive. But in 

 a field of corn there are a large number of stalks which do 

 not produce an ear, and have the tassel or staminate flow- 



