19(3 The Cross Folliiuition of Flax 



was already proceeding at that Institution. From certain of these trial 

 plots a number of plants were selected for tallness of branchless stem 

 and absence of tillei-ing, and these were " covered " separately. Some 

 additional plants were selected from some of the same plots on account 

 of their shortness of stem, and these were also " covered " separately. 

 Under these circumstances of isolation seed set abundantly. 



In the following year, 1913, the seed from the "covered " selected 

 plants were sown at Wye, each seed being sown separately one foot 

 apart in rows, which were also one foot apart so as to give each plant 

 a full opportunity for displaying its true character. It should be 

 mentioned also that throughout this work a method of labelling has 

 been adopted which has maintained the identity of each of the plants 

 originally selected. 



When the plants raised in this manner were about to come into 

 flower a similar selection was made again, and of the plants raised from 

 selected tall parents only those plants were " covered " which had not 

 tillered and which possessed relatively tall single stems — the measure- 

 ments being made in every case from the ground level up to the lowest 

 branch on the stem. In the case of the plants derived fi-om selected 

 short parents only short plants were selected and "covered." It appeared 

 evident at this stage of the work that if tall plants and short plants are 

 selected from one and the same crop, and these are properly " covered," 

 and the seed resulting from the selling of the covered plants is sown, 

 tallness generally characterises the plants derived from tall parents and 

 shortness those from short parents'. 



In 1914 a similar procedure was followed with regard to sowing the 

 seed obtained from the " covered " plants of the previous year, and it 

 was noticed again that plants selected for tallness and for shortness 

 breed true to those characters — an average difference of about twelve 

 inches in the height from the soil level to the first branch being 

 observed between those plants resulting from a repeated selection for 

 tallness and those repeatedly selected for shortness. 



With the object of ascertaining how far these efforts to eliminate 

 tillering had been successful and how far the general height of the crop 

 was likely to be increased, reference plots were arranged alongside the 

 plots of twice selected flax, upon which some of the various samples of 

 seed originally employed in 1912 were grown imder simibn- conditions 

 regarding distance apart. 



Upon making a comparison of the crop raised from the originally 

 ^ Vide Journ. Agric. Soc. England, 1913, lxxiv, 140. 



