112 THE COTTON PLANT IN EGYPT ch.vi 



zygotes and gametes for Indian varieties, but the 

 Egyptian examples are perhaps more striking, on account 

 of their higher economic value. 



Even in a uniform environment, therefore, a commercial 

 variety of cotton must change and may deteriorate. We. 

 might almost say that the change must be in the inferior 

 direction, since a successful new variety is mostly superior 

 to its parent stock, and will regress if contaminated by it. 

 A plausible fiction declares that the Hfe of a variety of 

 Egyptian cotton is limited to fifteen years. The kernel of 

 truth within this dogma should now be apparent to the 

 reader, and it should further be self-evident that the life 

 of a variety might be prolonged indefinitely by suitable 

 precautions. 



