COTTON VARIETIES 39 



(b) the method in which the progeny of a single ideal plant 

 is made the basis of a new variety. 



(3) Artificial crosses by which one or more of the im- 

 portant characters of both parents have been vmited in the 

 progeny. 



(4) Natural crossing resulting largely from the' trans- 

 ference of pollen by insects from the anthers of one variety 

 to the stigmas of another. 



Cotton improvement by selection and crossing is taken 

 up rnore in detail in a subsequent chapter. 



45. Stability of varieties. — Cotton varieties are sel- 

 dom kept pure. It is the common tendency for any im- 

 proved variety to degenerate if consistent selection is not 

 carried on every year. This' degeneration is partially due 

 to the rapid multipHcation of undesirable plants. 



When two different varieties of cotton are grown in 

 close proximity, a certain amount of crossing takes place 

 for the reason that insects carry pollen from flower to 

 flower. This tends to break the stability pf both varieties. 



46. Influence of soil and climate. — It is a well-known 

 fact- that a variety of cotton when grown for a number of 

 years under a given set of conditions, will gradually adjust 

 itself to its surroundings. The time required for complete 

 adjustment to take place varies with different varieties. 

 Some .varieties, of which King's Improved is an example, 

 require only one or two years in which to become adjusted 

 to almost any part of the cotton-belt. Others require from 

 three to six years. 



Some varieties are especially fitted to certain conditions 

 of soil and chmate and -usually are not profitable when 

 grown in new localities. There are even varieties best 

 adapted to poor lands. It is claimed that Beat-All, a 

 variety very popular in some parts of Georgia when grown 



