COMMERCIAL LINT 149 



The spacing of the convolutions from end to end of the 

 fibre would be determined at the same time as their 

 direction, and in the same way. 



In the third place we have to consider the " pitch " of 



the convolutions, which is of high importance. If the 



Uniformit P^ cn * s * l w the fibres cannot interlock 



and Pitch of properly, and if too high they will be Jiable 



Convolutions. to snar i j n preparation for spinning. At 



first sight it would appear that the pitch would be entirely 



dependent on the angle at which the pits were set to the 



axis of the cell, and this is undoubtedly an important 



component, as further investigations on the wild-cottons 



may show. 



In addition, however, the thickness of the wall affects 

 the convolutions, as can be easily realized on considering 



Pitch and * wo ex ^ reme cases. If a lint hair has an 

 Hair extremely thick wall, so that the central 



Strength, cavity is practically obliterated, it cannot 

 shrivel on drying, and therefore cannot form visible surface 

 convolutions, in spite of the presence of the pits ; if the 

 same kind of hair, with pits set at the same angle, is very 

 slightly thickened, the collapse on drying will be at its 

 maximum, and the convolutions will be entirely deter- 

 mined by the pitting. Thus intermediate stages will have 

 intermediate pitch in their convolutions. Regarding the 

 question in this way we bring the convolutions into line 

 with other properties of the lint which we have studied 

 in their development. Convolutions are primarily deter- 

 mined by the angle at which the pits are set probably 

 an inherited character and are modified from this by 



