NOTES OX COLOUR INHERITANCE IN MAIZE. 263 



this nature, 25 per cent, of grains purple) and that others were 

 heterozygous for either P or C (expectation, if all were of the 

 constitution Pc or pC, 50 per cent, of grains purple). 



Table 15 shows the effect of the pollen of the supposed 

 uniform series of plants recorded in Table 13 upon a series of 

 non-purple seed bearers of unknown constitution. As stated 

 in my earlier paper, the comparatively wide variation in the 

 percentage of purple grains on individual plants, in the case of 

 this series , must depend upon differences in the seed parents , 

 which we have no means of checking. Plant No. 8 is of special 

 interest. So low a percentage of purple grains as 13*7 per 

 cent, can only be accounted for by supposing that the seed 

 plant was heterozygous for an inhibiting factor (expectation 

 1 purple grain in 8, or 12*2 rfc 1 • 19 per cent.). 



It is not necessary to carry out a similar detailed analysis of 

 the whole of my former paper, but it may be stated that there 

 is no reason to doubt that all the supposed aberrant results 

 there recorded can be interpreted with the aid of the several 

 hypotheses put forward by East and Hayes. 



I may take this opportunity of replying to another and a 

 more serious criticism of my paper made by East and Hayes. 

 These authors write : " Lock mentioned that light yellow 

 seeds appeared in his crosses, but he classes them as whites, 

 which vitiates his study of Mendelian numerical proportions." 

 And again : " The occurrence of the two yellow colours casts 

 a further doubt upon the correctness of Lock's work, since his 

 main object was to show the truth of Mendel's mathematical 

 conclusions when dealing with large numbers." 



East and Hayes have overlooked the fact that the second 

 yellow factor made its appearance in two only out of a large 

 number of experiments. There was no sign of any such 

 disturbing factor in the experiment recorded in the table on 

 pages 139 and 140 of my earHer paper. Li the final stage of 

 that experiment, 95 plants, simply heterozygous in respect of 

 the yellow and non-yellow characters, were polhnated by a 

 non-yellow variety, and yielded a total of 26,792 yellow grains 

 to 26,751 non-yellow. It is quite clear that in the whole of 

 this experiment a single yellow factor only was concerned, and 

 the result remains — I venture to assert — the most complete 



6(3)12 (34) 



