COBN STRUCTURE 



Fig. 36. — Diagram showing Codkbe of the Pollen-tube through 

 Silk to Ovaht. 



A, section near outer end of silk, showing pollen-grain and pollen-tube : 



B, section through base of silk and through young grain. (Drawing by 



C. S. Ridgway.) 



The pollination of corn is effected almost entirely by 

 the wind, which may carry the pollen great distances. 



