462 Agnes Arber .■ — Studies on Intrafascicular Cambium 
longitudinal veins. This is conspicuously the case in Veratrum (Fig. 3, Lb .), 
and I have noticed the same thing in some of the other Liliaceae — Allium 
(Fig. 4), Kniphojia , Hemerocallis , and Anthericum — and in Iris orchioides . 
But I have not investigated the point fully enough to generalize upon it. 
In one case in Anigozanthos I observed a lateral vein whose xylem, though 
attached in part to the secondary elements, was also connected with the 
metaxylem ; but in the bundle drawn (Fig. 5) the connexion was apparently 
with the secondary xylem alone. 
Apart from the differentiation of the xylem, the leaf-bundles of 
Veratrum are of special interest as furnishing a conspicuous case of what 
we may call deferred cambial activity. The cambium formed in one season 
survives the winter, and is operative in the succeeding year. Fig. 1 shows 
a bundle belonging to a leaf taken in August from next years bud ; here 
cambium is already visible. Fig. 2 represents the stage reached by 
a similar bundle in March of the following year, when the cambium is 
actively dividing, while Fig. 3 shows the bundle in July when it is fully 
mature and all the work done by the cambium can be recognized. A 
Monocotyledonous bundle in which cambium is active in two succeeding 
seasons has hitherto been described in only one case — that of the tubers of 
Gloriosa superba L. 1 But no doubt other examples will come to light 
when organs which persist through two or more years are examined from 
this point of view. 
IV. New Records of the Occurrence of Intrafascicular 
Cambium. 
Since the publication of my former list of Monocotyledonous families 2 
in which the occurrence of cambium has been recorded, I have observed it 
in the following additional cases 
JUNCACEAE. 
Juncus glaucus Sibth. In the leaf-bundles there is distinct cambial 
activity, which seems — as is generally the case in the related Liliaceae — to 
be chiefly directed to phloem production. 
Haemodoraceae. , 
Anigozanthos sp. Cambium occurs in the leaf-bundles and gives rise 
to both xylem and phloem elements (Fig. 5). 
Amaryllidaceae. 
Narcissus pseudo-narcissus L. (garden var.). In the mature leaf, traces 
can be detected of a cambium which gives rise to phloem — possibly also to 
xylem elements. 
1 Queva, C. : Contributions a l’anatomie des MonocotyHdondes. 1 . Les Uvulariees tubereuses. 
Trav. et Mem. de l’Universite de Lille, T. 7, Mem. xxii, 162 pp., n plates, 1899. 
2 Arber, A. ( 1918 ), l.c. 
