118 Harris AND AvERY: MORPHOLOGICAL VARIATIONS 
ment. A leaf with three leaflets, one of which has a lobe, has been 
recorded as 3 in the tables, not as an intermediate between three 
and four. This has simplified the tabling of the data, and the cal- 
culation of the simple constants necessary to the interpretation 
the data, without any material loss in accuracy. 
One may, however, inquire whether there are differences in the 
degree of lobing of the leaflets produced at the third node in plants 
which are normal and in plants which are abnormal in the char- 
acters of the first and second node. Because of the very low per- 
centages of lobing in the leaflet no stress whatever is to be laid 
upon the exact values found, even in samples containing several 
hundreds or thousands of plants, because of the great difficulties 
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 
: I Sontrol ‘ 
Cla fah lity peat ype Difference 
_ leaves See Deere teense Se ee 0.349 0.273 +0.076 
WORN CES 0.456 0.112 +0.344 
Three cotyledons; two primordial leaves ............. I.599 0.242 +1.357 
three primordial leaves ........... 0.954 0.328 | +0.626 
Here the percentage frequency of plants with one or two lobes 
on the leaflets* are given for each type of abnormality dealt with 
and compared with that found in the control series. 
Two relationships seem clearly indicated by the constants in 
this table. 
First, the tendency to the production of lobes is greater in the 
leaflets produced by abnormal plants of all four types than in 
their normal controls. 
Second, the tendency to the production of lobes is greater in 
the leaflets of plants with a trimerous cotyledonary whorl, and 
either a dimerous or trimerous primordial whorl, than it is in 
plants in which the sole abnormality consists in the separation of 
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 be on 
different leaflets. 
