12 INHERITANCE OF SOME CHARACTERS IN WHEAT. 



involved the microscopic examination of nearly 15,000 plants and 

 that considering the difficulty of the work the numbers obtained 

 correspond very fairly well with expectation. A considerable num- 

 ber of cultures were examined in the class (SsLl), which gave the 

 15:1 ratio, but time did not permit of the detailed examination of 

 more than 831 plants belonging to 10 cultures. The ratio felted 

 to smooth, however, was worked out for 3,912 plants belonging to 35 

 more cultures. There can be little doubt that had time permitted 

 for the examination of these 3,912 plants they would have con- 

 firmed the ten cultures of this class which were worked out in detail. 

 The complete study of the F 3 generation enabled us to examine 

 the 1,017 plants of the F,. After the examination of the F 3 it was 

 easy to obtain a representative plant of each of the eight classes of 

 differently felted plants which occurred in the F 2 . By mounting 

 a glume of each of these representatives on a slide a set of standards 

 was obtained by the aid of which it was possible to divide the F. 2 

 material into its constituents. A glume of each of the 1,017 F 2 

 plants was compared with the standards and the class was deter- 

 mined by inspection. The results are given in table VI and it will be 

 seen that the figures obtained compare fairly well with expectation. 

 Even with these standards it was sometimes difficult to determine 

 the proper class to which an individual belonged. For example, 

 in distinguishing plants of the gametic constitution S S 1 1 and s s 

 L 1 the difference is mainly one of density of the felting, the partially 

 developed long hairs being of almost the same length as the 

 completely developed short ones. A similar difficulty arose with 

 plants represented by S S L L and S s L L. 



