VI COMMERCIAL VARIETIES 109 



F;^ — or more probably several years before, in wbich case 

 the plant may be denoted as F^. In this second case we 

 are dealing with an entirely different set of phenomena, 

 superadded to fluctuation. The segregation of the 

 character-bearing factors in sex-cell formation, with their 

 reunion into new combinations at fertilisation, produces a 

 set of offspring which differ constitutionally amongst them- 

 selves. The complexity of these differences will depend 

 on the number of characters in which the original plant 

 was heterozygous. 



An example of such a plant may be quoted from the 

 author's records. In 1909, while examining an old field- 

 book of 1905, a note was found which gave the names of 

 plants in flower at a very early date. They were all 

 Uplands with one exception. This exception was a group 

 of plants grown from a boll of Kerki, called No. 95. The 

 few seeds available were taken from the files and sown, in 

 1910, since an early-maturing Egyptian stock was much 

 needed. Only five plants were raised, of which four were 

 slightly stunted, while the best and earliest was found in 

 the autumn to bear an inferior and quite distinct type of 

 lint. Whether this plant was an F;^ from 1905, or an F^ 

 from an earlier cross, our records could not disclose. The 

 former is more probable. The remaining four were again 

 fertilised naturally, and four families raised in 1911. They 

 were fairly early, and — except for a few natural hybrids 

 from crossing in 1910 — were uniform in most respects 

 excepting height. The original plants had been irregular 

 in height, owing to stunting, but the offspring gave the 

 following figures for height in October. 



Inspection of the frequency curves showed that No. 95. 

 C. 2 was breeding true to shortness, 95. C. 4 probably 



