118 HARRIS AND AVERY: MORPHOLOGICAL VARIATIONS 



ment. A leaf with three leaflets, one of which has a lobe, has bee 

 recorded as 3 in the tables, not as an intermediate between thre 

 and four. This has simplified the tabling of the data, and the ca 

 culation of the simple constants necessary to the interpretatio 

 the data, without any material loss in accuracy. 



One may, however, inquire whether there are differences in th 

 degree of lobing of the leaflets produced at the third node in planl 

 which are normal and in plants which are abnormal in the cha- 

 acters of the first and second node. Because of the very low pe 

 centages of lobing in the leaflet no stress whatever is to be lail 

 upon the exact values found, even in samples containing seven 

 hundreds or thousands of plants, because of the great difficult^ 

 of determining the probable error of a small percentage. 



The results are given in TABLE X. 



TABLE X 

 PERCENTAGE OF LOBING IN THE LEAVES OF SEEDLINGS OF VARIOUS TYPES 



Here the percentage frequency of plants with one or two lob* 

 on the leaflets* are given for each type of abnormality dealt wr 

 and compared with that found in the control series. 



Two relationships seem clearly indicated by the constants 

 this table. 



First, the tendency to the production of lobes is greater in 

 leaflets produced by abnormal plants of all four types than 

 their normal controls. 



Second, the tendency to the production of lobes is greater 

 the leaflets of plants with a trimerous cotyledonary whorl, ai 

 either a dimerous or trimerous primordial whorl, than it is 

 plants in which the sole abnormality consists in the separation 

 the two cotyledons in their insertion on the axis of the plant. 



* In the case of two lobes both may occur on the same leaflet or they may 

 different leaflets. 



