288 DR. P. GROOM ON THE LONGITUDINAL 
In this comparatively young and actively growing plant it was not possible to tell the 
15. 
extent to which the internodes had attained their full length. The internode-curve is 
regular and normal except for the final slight rise. 
AMARANTACE.E. 
This family includes both alternate- and opposite-leaved types, and species of both 
kinds were measured. The alternate-leaved plants belonged to the genus Amaranthus, 
the opposite-leaved plants to the genera Gomphrena and Froelichia. 
The species with cyclic phyllotaxis exhibited regular internode-curves, which strongly 
contrasted with the extremely irregular internode-curves of the alternate-leaved species. 
The sudden and frequent irregularities of the latter clearly indicated displacements of 
the leaves, yet analysis of the internode-curves did not yield two regular subcurves. 
Consequently it is impossible to decide whether the plants signify a transitional condition 
from cyclic phyllotaxis with two or more leaves at a node towards acyclic phyllotaxis, or 
the reverse. At least the facts denote leaf-displacements due to inherent characters. 
Yet in the alternate-leaved types the primitive opposite phyllotaxis is suggested by the 
divergences of the leaves at the base of the main stem, which agreed exactly or approxi- 
mately with those of decussate phyllotaxis. 
In this family the phenomenon of fasciation in connexion with the terminal inflores- 
cence is closely akin to fusion of branches with the main axis in Phytolaccacee and 
Chenopodiaceze. In all cases it is probably to be attributed to precocity of outgrowth of 
branches. 
GOMPHRENA DECUMBENS. (Curves 16m, 16 1-v1.) 
This annual, opposite-leaved plant was uprooted. From the base of the main stem 
sprang a number of procumbent branches and accessory branches, so that it was not 
easy to see instantly which was the main axis; and exact measurements of the lower 
internodes of this were out of the question. 
The cotyledonary scars subtended buds. The branches in the axils of the first pair 
of foliage-leaves are termed Branches I and I’, those in the axils of the second pair of 
leaves Branches II and II’, and so forth. 
