ii2 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 life 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. 



