SYMMETRY OF THE CENTROSPERM X. 271 
represented a form transitional between the prostrate and erect form, as, despite of its 
erect main stem, the lowest two branches were prostrate, and the next two higher ones 
were slightly descending : moreover, in typical erect forms the branches emitted from 
the base of the main stem are less developed (at least early in life) than those inserted 
at some distance higher. 
Internode-curves of Atriplex rosea. | 
Measurements were made along not only primary and secondary, but also tertiary and 
quaternary axes. They show the general truth of the following conclusions :— 
1. The internode-curves are zigzag, and those of the branches are often also irregular, 
but can be analysed into two regular or consistent subeurves—internode-subeurve and 
displacement-subcurve. 
2. The subcurves of the main axis and lower secondary axes are of the ascending- 
descending (normal) type, but in branches successively inserted higher up the axis 
they change towards a purely descending type; and in this change, thanks to the 
disproportionate gain in length of the proximal segments (early ordinates), an 
additional maximum (or minimum) is introduced into the subcurve. The subcurve 
recording the leaf-displacements usually undergoes the change later than the internode- 
subcurve. 
These statements are proved by the subjoined statistics referring to specimens termed 
Iss, LI 10, 191, 192, 187, IL 12 Er’, 114 Hr’, 118 Er*, and represented by Curves 1-5. 
Regular Ascending-descending Subcurves shown by :— 
Nature of Tit 3 beurre. Displacement-subcurve. 
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| Main axes ...... Iss (Curve 1 m). Iss (Curve 1 m). 
Secondary axes ..| Relatively main axis of 192 (Curve 3m). | Iss, Branches 1-4 (Curves 1 1, 1 11). 
I10, Branches 1, 3, 4 (Curves 21, 2 11). 
192, Relatively main axis (Curve 3 m). 
191, i ee (Curve 4 m). 
| Tertiary axes....| 192, Branch 1 (Curve 3 1). 192, Branches 1, 2 (Curves 31, 3 11). 
| 191, Branch 2 (Curve 4 1). 
Mustetnary axes ] | — ee TT 187, A 1 (Curve 51). 
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