18 THE DEVELOPMENT OF EAW COTTON 



in the laboratory. Strains can therefore be kept pure on 

 a small scale, and a fresh stock run up into bulk (PL VI.) 

 each year to replace the contaminated descendants of pre- 

 vious years. The system was introduced into Egypt by the 

 writer, and at the time of writing is in abeyance through 

 misunderstanding of the complexities involved in the 

 isolation and testing of new strains; but it will inevitably 

 become general before many years have elapsed in all 

 countries supplying fine cottons to the trade. Whether 

 it will ever be worth while to apply it to coarser cottons 

 remains to be seen, but though uniformity is less im- 

 portant in inferior cottons, the possession of it still in- 

 creases their value, and the question of yield is also worth 

 consideration. 



In such a country as Egypt the limiting factcr of the 

 yield is the conditions under which the plants are grown, 

 and it is a little doubtful whether any change 

 |? ^ n in the type of plant cultivated could increase 

 the yield appreciably, though the author is 

 inclined still to think that this could be done. In India, 

 on the other l^and, and in most countries dependent on 

 rainfall, the conditions of cultivation cannot be so pej- 

 fectly controlled, and the problem is rather one of how to 

 produce and maintain varieties which will give the best 

 results under the existing average conditions. The re- 

 searches of Mr. Leake on the breeding of branching habits 

 and of ginning out-turn may be cited as an example of 

 the beginning of such work, and the logical outcome of 

 any such developments must also be the supply of pure 

 seed and provisions for its renewal. 



