112 Harris AND AVERY: MORPHOLOGICAL VARIATIONS 
and personal equation may influence in some degree the classifica- 
tion of the seedlings. 
The second is a division of the axis into two coérdinate branches 
each with a terminal bud. 
The frequencies of the two types of axial variation are too small 
to justify detailed discussion. The entries in TABLE I show that 
TABLE I 
FREQUENCIES OF ABNORMALITY OF SECOND INTERNODE IN NORMAL AND ABNORMAL 
SEEDLINGS 
| Actual frequencies Percentage frequencies 
| ——___—____— 
. Broad-| Di- 
ee eee. ‘Norma ened | vided | Normal | Broadened| Divided 
inter- | inter- | internode | internode | internode 
‘node node node 
Two cotyledons slightly siseiuia: | 
two primordial leaves.......... 4,017 5 8| 090.6774 .1240 -1985 
PROFIAL CONEIOD. 6 eva ee fies o 4,029 (a) El GO.OFGE| feu near .0248 
* erenCe ee Fb ee oe cs —12| + 5| + 7} —-2077| +. .1240| +.1737 
Two cotyledons sien As grasa 
two prim ye 55 leavea eGo yes 878 2) I} 99.6594 .2270 +1135 
Normalcontrics 25 ccs eee ss 881 oO | ROO 0600 Soe Te ye. 
Diff bes be 2 AGE oh 2990) 4 35 
ere: cotyledons; two primordial 
WOR ee Ve haces see ee 813 12 GO} O8;5454| 5.45401... .. 
Peak PORNO fore a 825 ° © IO 00CG Fo a eo 
Difference aed —I2} +12 @} 1.4546) 4+-1.4546] ...... 
Three cotyledons; three primordial . 
VOR eae a5 .| 2,410 14 14} 98.8515 -5742 -5742 
Norinal control... 2,436 2 0| 99.9179 ORI vies. 
Diflerénce. 525 3 | —26| +12} +14) —1.0664| + .4922] +.5742 
in every instance in which any individuals at all are available the 
seedlings which are abnormal in either the cotyledonary or the 
primordial node show a higher percentage of abnormality in the 
structure of the internode beyond the second node than do the 
normal controls. 
We now turn to a consideration of variation in the leaves in- 
serted at the third node. The leaves of plants with abnormality 
of the axis should not be combined with those having normal axes, 
They are not sufficiently numerous for separate consideration. 
Confining our attention to seedlings which have a normal axis 
for at least the length of the second internode of the epicotyl, we 
