TENOPYR: CONSTANCY OF CELL SHAPE 65 
All cases where there were four and a fractional part of a cell 
to 0.232 mm. were recorded as four cells—all cases of more than 
five cells and less than six cells were recorded as five cells, etc. 
These curves show that both in the long axis and in the transverse 
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A B 
Fic. Curves denoting frequency of dimensions of lower epidermal cells of 
ie seats rotundifolia , Transverse axis. B, Longitudinal axis. Abscissas 
denote the number of bells to 0.232 sastitaien Ordinates record the n 
instances in which a given number of cells per 0.232 mm. occu U cai lines 
used for cells of basal leaf; lines broken by x’s, for linear stem leaf. 
axis of the leaf, there are most frequently five cells to 0.232 mm. in 
the basal leaf, while in the linear leaf there are six. The curves 
prove conclusively that the decrease in both dimensions of the 
lower epidermal cells of the linear leaves is regularly present in the 
material studied. 
This observation agrees with that made by Sierp, who found 
that in Mirabilis Jalapa, Nigella damascena, and Pisum sativum 
(Laxton’s Alpha) the higher the leaf was situated on the stem, the 
smaller its cell size, as well as that of the node from which the leaf 
sprang. 
