150 THE DEVELOPMENT OF RAW COTTON 



the extent and regularity of the thickening of the wall, 

 excessive thickening reducing the pitch of the convolu- 

 tions. The pitch of the convolutions which gives the 

 best result from any variety of cotton in any particular 

 class of spinning operations is in all probability definite 

 for that class. 



It would seem, therefore, justifiable to assume that 

 although no precise data of the kind we require have 

 ever been obtained as to the varying development of the 

 convolutions, yet in all probability the same considera- 

 tions apply as in the case of length and hair strength. 

 All the factors, constitutional or environmental, which 

 modify the latter from ideal uniformity, also modify the 

 convolutions in a parallel way. 



Uniformity. Throughout the whole of our discussion 

 of the development of raw cotton there has been one 

 recurrent ideal, namely, the production of uniform cotton. 

 By various stages of analysis we have seen how it is 

 possible to attain an approximation to this ideal, and 

 how the difficulties may all be overcome if it pays to 

 do so with the exception of such irregularities as are 

 due to the " struggle for existence " between individual 

 hairs on the same seed. 



The fact that we have had to carry our analysis into 



Perfect such minute details, and to link these up 



Cotton with such remote causes, shows very clearly 



Unattainable, that, however interesting the knowledge may 



be, a strictly uniform sample of cotton-lint can never be 



grown. 



Equally, however, our analysis shows how very far 



