88 
Arber.—Further Notes on Intrafascicular 
ephemeral. It was only observed in sections so close to the apex that the 
diameter of the axis was about i mm., or, excluding the prominent leaf- 
bases, o*5 mm. 
Tritonia , garden hybrid (Iridaceae). Traces of cambium were observed 
in the bundles of the very young inflorescence axis, at a stage when the 
diameter of the axis was less than 075 mm. 
Potamogeton natans , L. (Potamogetonaceae). In this species, evidence 
of very slight and irregular cambial activity has been found in the vascular 
bundles of the leaf. The same thing has been noticed in the leaves of 
another species, probably P. lucens , L. 
Ophiopogon japonicus , Ker-Gawl. (Liliaceae). In transverse sections of 
the inflorescence axis, the bundles are seen to be arranged in a ring. At a 
very young stage there are clear indications of cambial action. The radial 
rows of elements within the bundle in some cases involve xylem as well as 
phloem. 
Phormium tenax , Forst. ('Liliaceae). Both the xylem and phloem of 
the mature leaf-bundles show indications of cambial activity. 
Veratrum album , L. (Liliaceae). 
In the mature leaf the arrangement 
of the phloem elements in radial files is 
; particularly striking. 
List of Cohorts and Families in which 
one or more cases of intrafascicular 
cambium have been recorded} 
Pandanales 
Typhaceae 
Helobiae 
Potamogetonaceae 
Scheuchzeriaceae 
Glumiflorae 
Gramineae 
Cyperaceae 
Principes 
Palmae 
Spathiflorae 
Araceae 
Farinosae 
Commelinaceae 
Liliiflorae 
Liliaceae 
Dioscoreaceae 
Iridaceae 
SCITAMINEAE 
Musaceae 
Zingiberaceae 
Microspermae 
Orchidaceae 
It follows from this list that intrafascicular cambium is now known 
from all but two of the cohorts into which Engler divides the Monocotyle¬ 
dons ; the exceptions are the Triuridales and the Synanthae. The Triuri- 
dales consist of a small group^of tropical saprophytes, which are not avail- 
1 The references to the literature in connexion with these records will be found in my previous 
paper, already cited. 
