292 DR. P. GROOM ON THE LONGITUDINAL 
| ETT Cel eee z Hit | | ao ao ane 
| | | | 
| Main axis... .|4°5 (circa) 4:5 (circa), 5 (circa) | 10 | 96:5 | 346 ? | End broken off. 
| | | | | A 
| (BranchI....| 165 575 | 112 165 Dur won .. | Ends in a long internode broken off at 4 
| | | | length of 280 mm. 
| V dn d | 45 | 99 | 148 | eae Ends in a long broken internode. 
| | | | | 
| Tete cae RIE a | 100 | 130-514169 | ? | Ends in broken and decayed internode. 
| $ iu le 62:5 | 129 | TOI | 115 | ? | "E DE » E] " | 
1 SINE E Sa 69 130 | 182.5 | | TREE .. | Ends in decaying internode broken at. 
| | | length of 180 mm. 
| | d 
TED n ES yi 134:5 143 | 253 x 35 16°51 7 Ending in short internode capped by ter- 
f AR EV. T 144 158 | 278x 42 22:5 | T5 minal inflorescence. 
UA d 53 98:5 130 | 91:5 x 6 Ending in terminal inflorescence. 
| 
S EP E Ld 89:5 1545 (1275x | 12 4 " »» : 
TI hi ex 13:5 63:5 105 98 x t ” ” ” 
the insertion of the branch rises. 
arrangement was cyclic, with two leaves at a node. 
All the parts measured had attained their mature length. 
The regularity of the internode-curves is striking, as is the agreement between those 
of the pairs I and I', IV and IV’. The basal branches seem to have ascending internode- 
curves, but this is due to the fact that the terminal parts were decayed and had fallen. 
None of the branches show the descending form of internode-curve, yet Branches I to 
IV’ display the extremely regular gradual increase in length of the basal internode as 
AMARANTHUS RETROFLEXUS and A. POLYGONOIDES. 
The internode-curves of these alternate-leaved species contrast excessively with those 
of the opposite-leaved Amarantacez. The main axes of both show very irregular 
internode-curves, suggesting displacement. 
be analysed into two regular ascending subcurves, on the assumption that the primitive 
At the commencement of the 
curve it can 
But soon the internode-curve 
becomes irregular, and the subcurves produced by the same analysis are also irregular. 
In both cases the repeated maxima are alternately separated by three and five leaves; 
such a condition would be produced if the arrangement were primitively composed of 
nodes with alternately three and five leaves, and these had been relatively displaced, but 
the original internodes had still continued to be longer than the displacement-segments. 
The measured branch of A. retroflexus, on the contrary, produced an internode-curve 
that analysed into two regular subcurves, disturbed only at one point in th 
internode-subeurve. 
AMARANTHUS RETROFLEXUS. (Curves 19 m, 19 x.) 
e case of the 
This alternate-leaved annual plant was uprooted, and the measurements Were 
commenced at the lowest indubitable leaf-scars, which were opposite and probably wer 
ere Es tee ee eg ee oe 
