20 



SUCCESSFUL FARMING 



due to differences of environment, and in this case will not be inherited. 

 If a hill of corn is heavily manured, the stalks and ears will be larger 

 than where manure is withheld, but seed from these favored hills is not 

 necessarily any better than seed from plants not so well fertilized. How- 

 ever, variations may arise which are hereditary and which may be the 

 beginning of new varieties. When the variations are in the yield or size 

 of plant, usually one cannot distinguish the difference between the varia- 

 tions which are hereditary and those which are not, except by a study of 

 the progeny of the plants. When the variations are in color or form, 



; ■ ' ■'■-■" V"'" - "":■• ..,"•:''" '"'■■ : '' 



Variations in Timothy. 1 



one may have less difficulty in picking out those which could be used to 

 develop new strains or varieties. 



Hybridization. — Hybridization means the crossing of plants of dif- 

 ferent species or different varieties. It is accomplished by taking the 

 pollen from a flower of one of the plants to be crossed and placing it on 

 the pistil of a flower of the other. Care must always be exercised to pre- 

 vent the plant-producing seed from being fertilized with its own pollen 

 or with foreign pollen carried by the wind or by insects. 



While there has been a good deal of mystery to many in regard to 

 the crossing of plants and a disposition to regard hybrids as of superior 



i Courtesy of The Macmillan Company, N. Y. From!" Plant Breeding," by Bailey, 



