156 BOTANICAL GAZETTE [SEPTEMBEK 



with the total weight in the control plants irrespective of the 

 number of primordial leaves formed by the individual plants of the 

 tetracotyledonous race. The total number of leaves per plant, 

 however, was determined in these four series. 6 Thus it is possible 

 to give the average weights both per plant and per leaf in the two 

 series. The results show that in three of the four cases the green 

 weight as given in table I of the approximately four primordial 

 leaves of the tetracotyledonous race is lower than that of the two 

 primordial leaves of the dicotyledonous strain. The percentage 

 differences in total weight range from +2.1 to 16.4, with a 

 general average of 7.37. When the comparison is made on the 

 basis of mean weight per leaf, the primordial leaf of the abnormal 

 seedling is found to be on the average 54.22 per cent lighter than 

 the leaf of the normal seedling. 



For dry weight, given in table II, all four series show lower 

 average weight in the tetracotyledonous strain. The percentage 

 differences for dry weight of primordial leaves per plant vary from 

 i .6 to 18 .o, with a general average of 10 .90. On the basis 

 of mean dry weight per leaf, the weight for tetracotyledonous plants 

 is found to be from 49 . 6 to 59.9 per cent lower than that of the 

 normal seedling, with a general average percentage difference 

 of 55.92. Thus the results for these four samples clearly indicate 

 that an abnormal race shows the same relationship to the normal 

 parental race as do abnormal individual seedlings to the normal 

 seedlings in the same race. 



PLANTS CLASSIFIED WITH RESPECT TO NUMBER OF PRIMORDIAL 

 LEAVES. Upon the completion of this preliminary comparison it 

 seemed worth while to analyze the relationships more minutely 

 by considering individually the results for seedlings of the tetra 

 cotyledonous race with varying numbers of primordial leaves. 

 These results were only attained at the cost of great labor, since 

 it was difficult to secure considerable numbers of seedlings of any&quot; 

 given type simultaneously. It was necessary, therefore, to make 

 determinations for abnormal and control plants in small sub- 

 samples, and to combine these to form samples of 100 seedlings 



6 The average numbers per plant were as follows in the four samples: 226=4.07, 

 227 = 4.15, 228 = 4.10, and 229 = 3.91. 



