168 THE DEVELOPMENT OF EAW COTTON 



less, unflagging, searching accuracy in handling the ma- 

 terial (PI. I., VI., X., XIII., XIV.). 



Roughly summarized, but with most rigid definition of 

 every word, it consists in obtaining seed from single 

 plants by self-fertilization exclusively, until plants are 

 found which give offspring all exactly alike constitution- 

 ally in every visible and measurable feature. 



There seems to be some conviction at the back of many 

 minds that a new kind of cotton can only be obtained by 

 multiple crossing, destruction of organic stability, in- 

 crease of tendency to reversion, interference with the 

 balance of nature, and consequent aftermaths of like 

 vagueness. Actually the production of pure strains is 

 as straightforward and definite a process as the separa- 

 tion of sugar from sand . 



The cost of such work is high, however, even if the 

 actual purification research is not charged to it. To 

 maintain a single pure strain from year to year, avoiding 

 all contamination by crossing and mixture, cannot be 

 done at a cost of less than about 50 per annum for a 

 renewal supply of only 20 kilogrammes of seed, merely for 

 appliances (PI. XIII., XIV.), and without counting the 

 cost of skilled labour. It would be to the interest of new 

 countries to develop pure-strain cultivation as quickly as 

 possible, when the old countries have strains to spare, for 

 Development man y suc h strains will be isolated and tested 

 of Pure-Strain and found to be slightly unsuitable for the 



Breeding. country of origin, and yet might be per- 

 fectly suitable for some other country. One of the coming 

 features of the cotton trade in this respect will be an 



