GOSSYPIUM 445 



At this stage, the lint can be differentiated from the fuzz by the 

 relative size of the two types of epidermal outgrowths. The devel- 

 opment of fibers from the epidermal cells may continue for several 

 days after flowering, and Anderson and Kerr suggest that those 

 produced during the first two or three days become the lint while 

 the hairs that are formed later become the fuzz. Brown (9) at- 

 tributes the differentiation of some of the epidermal cells into lint 

 and others into fuzz, to hereditary characters; pointing out that, 

 regardless of cultural conditions, certain varieties always have a 

 low percentage of lint in comparison with the amount of fuzz, 

 while others have a relatively high percentage of long hairs. 

 While the two types of hair initials are at first similar in structure, 

 they become very unlike at maturity. The lint may vary in length 

 from % to 1. inches, while the fuzz remains very short. 



In connection with the origin of the later formed fibers, Farr (16) 

 has shown that they do not all arise from the original epidermal 

 cells, but from daughter cells which have been derived from the 

 former by cell divisions that occur subsequent to flowering. There 

 is a thirty-two-fold increase in the surface area of the ovule during 

 the first twenty days of its development, and only a two-fold in- 

 crease in the surface dimensions of the epidermal cells. The 

 increasing surface area cannot be accounted for entirely on the basis 

 of cell enlargement, and continued cell divisions of epidermal cells 

 must occur, to compensate for the growth of the maturing ovule. 

 This fact is in harmony with the recent findings relative to con- 

 tinued fiber formation. 



The nutrition of the develop ng fiber was attributed by Barritt 

 (7) to liquid in the intercellular spaces of the boll cavity, but Farr 

 (14) regarded this as unlikely and failed to find any evidence of 

 "a liquid or semi-liquid substance in the boll cavity." It seems 

 probable that nutrition during the development and maturation of 

 the fiber takes place only through its basal connection with the 

 adjacent tissues of the integument. 



The lint usually attains its full length by the end of the fifteenth 

 to twenty-fifth day of growth, the period of elongation apparently 

 depending upon several factors, including environmental condi- 

 tions, the time of the year that the flower opens, as well as the 

 variety. Following this, the second phase of fiber development 

 begins involving secondary wall thickening. Earlier investiga- 

 tions by Balls (5) have been confirmed by Kerr (xx) with respect 



