CELL MEASUREMENT 
20I 
Whatever the cause of the variation within the internode, it is 
obvious that tissues for cell measurement should be taken from strictly 
comparable regions in the plant. It would seem to be a safe rule that 
in studies of the stem the tissue should come from the middle of the 
internode, unless a sufficiently large number of cells are measured so 
that an equal number can be taken from each aliquot part of the inter- 
node. 
Table IX 
Length in Mm. of Epidermal Cells Taken at Random Including Undivided Primary 
Cells and Secondary Cells from Epicotyl of Plant Grown in the Dark 
Class 
Section 
Entire 
Internode 
I 
2 
3 
4 
5 
6 
7 
8 
9 
10 
.030-057 
2 
0 
3 
0 
I 
0 
0 
2 
3 
3 
14 
.060-.087 
22 
22 
24 
8 
8 
II 
5 
6 
12 
13 
131 
.090-. 117 
41 
32 
37 
25 
48 
31 
21 
23 
19 
36 
313 
.I2O-.I47. ...... 
21 
30 
27 
37 
29 
33 
39 
25 
33 
17 
219 
'I5O-.I77 
12 
13 
9 
25 
10 
17 
22 
16 
15 
22 
161 
.180-207 
I 
3 
5 
4 
7 
9 
5 
13 
8 
55 
.210-237. ...... 
I 
I 
3 
II 
3 
I 
30 
.240-267. ...... 
I 
7 
2 
10 
.270-297 
3 
3 
.300-327 
2 
2 
Table X 
Length in Mm. of Secondary Epidermal Cells of Epicotyl of Plant Grown in the Dark 
Class 
Section 
Entire 
Intei-node 
I 
2 
3 
4 
5 
6 
7 
8 
9 
ID 
.030-057 
2 
3 
3 
9 
I 
0 
0 
2 
3 
2 
25 
.060-087 
31 
24 
25 
32 
8 
II 
6 
5 
10 
10 
162 
.090-. 117 
44 
37 
37 
42 
49 
32 
23 
22 
16 
33 
325 
.120-147 
18 
27 
26 
21 
29 
30 
42 
24 
33 
18 
268 
.I5O-.I77 
5 
9 
9 
4 
10 
17 
18 
20 
18 
25 
135 
.I80-.207 
2 
3 
7 
8 
4 
14 
8 
46 
.210-237 
3 
3 
II 
4 
2 
23 
.24O-.267 
I 
6 
2 
2 
II 
.270-297 
4 
4 
.300-327 
2 
2 
Kraus assumed that the quotient of the length of the internode 
divided by the mean length of the cells would bear a simple relation- 
ship to the number of cells making up the length of the internode. 
Since there is considerable dovetailing of the cells between one another, 
the quotient does not, of course, indicate the number of cells in a 
