172 



BROOKLYN BOTANIC GARDEN MEMOIRS 



The primordial leaves of the abnormal plants in which the two 

 cotyledons are slightly separated are, as shown in Table II, lighter 



Table II 

 Mean Dry Weight per Plant of Primordial Leaves and of First Compound Leaf 



than those of the normal controls in every instance. The average 

 dry weight of the abnormal is .0382, that of the control .0452 and the 

 average difference is —.0070 grams. If the differences be expressed 

 as a percent of the control value as a base, they range from less than 

 I to nearly 33 percent, with a general average of 15.21 percent. 



The results for the first compound leaf are very similar. In 22 of 

 the 23 cases the primordial leaves of normal plants yield a greater 

 weight of dry substance than those of the abnormal plants. The 

 exception to the rule is again sample 47. The average dry weight 

 of the first compound leaf of abnormal plants is .0385, that of normal 

 plants is .0452 and the average difference is —.0067 grams. If the 

 differences be expressed as percentages of the control constants they 

 are seen to range from 3.2 to 26.2, for the 22 series in which the ab- 

 normal plants produce a smaller amount of dry substance. The differ- 

 ence in the single exceptional series is small, only 2.1 percent as com- 

 pared with a general average of 13.36 percent in the 23 samples. 



