IX HEREDITY 173 



the superposition of a small-seed mode on the flank of a 

 large-seed mode. 



Summarising the evidence, it would seem that beneath 

 all the complexity involved by fluctuation, by autogenous 

 fluctuation and by correlation, there existed in all these 

 hybrids a straightforward segregation of seed-size, con- 

 trolled by a single allelomorphic pair of factors . in every 

 case. 



The mean maximum length of the lint. — The 

 inheritance of this character has been curiously similar 

 to that of seed-weight, but the evidence is not so clear. 

 The Afifi X Truitt cross showed segregation which was 

 ostensibly simple, long being dominant over short ; the 

 Charara x King cross gave dominance of length in Fj, 

 with subsequent modal composition in Fj. Sultani x 

 Afifi again gave dominance of length, and the Fj curve 

 was almost symmetrical between the parental extremes 

 (Fig. 70). 



Subsequent generations have shown that pure parental 

 length can be extracted, while new intermediate lengths 

 may also breed true. 



Dissection of the Fj revealed a similar series of 

 phenomena to those shown by seed-weight. In this case, 

 the most definite result was obtained by grouping to seed- 

 weight; the 28 largest seed- weights had a mean lint- 

 length which was 5'9 per cent, above the general mean, 

 with modes at 26^^ and 32 mm., the form of the dis- 

 section being that of the 3 : 1 type (Fig. 70). Conversely, 

 the 27 smallest seed- weights were 5 "9 per cent, below 

 the mean general lint-length, with modes at 21 and 

 27 mm. 



It thus seems highly probable that lint-length is also 

 inherited simply, in spite of the seeming complication 

 of the Charara x King second generation. 



Miscellaneous. — All the characteristics mentioned in 

 the chapter on Fluctuation have been made the subject of 



