Studies on Intrafascicular Cambium in 
Monocotyledons. V. 
BY 
AGNES ARBER, D.Sc., F.L.S. 
(Keddey Fletcher- Warr Student of the University of London). 
With eight Figures in the Text. 
I N previous papers in this Journal, 1 I have drawn attention to cases of 
the occurrence of intrafascicular cambium in a number of monocotyle- 
donous families. Recently the exhaustive researches of Mme Gatin- 
Allorge 2 on the anatomy of the peduncle and flower in the Liliiflorae have 
demonstrated that the occurrence of intrafascicular cambium may be treated 
as a universal character of the peduncle of the Liliaceae, Iridaceae, and 
Amaryllidaceae, and that the enlargement of the bundles observed in these 
families, at the level at which branches are given off to supply the conduct- 
ing strands of the flower, is due to the activity of this cambium. In 1917 
Dauphine 3 published an exquisitely illustrated account of the intrafas- 
cicular cambium in Dracaena — a tissue whose existence has already been 
recognized by Froken Sigrid Andersson, 4 but which bears no relation to the 
meristem responsible for the anomalous secondary thickening so well known 
in the genus. The work of these authors, and that of Lonay on Ornithoga - 
him , 5 Chauveaud on Liliaceous and A maryllidaceous seedlings, 6 and Queva 
on the rhizomatous Uvularieae 7 and the Dioscoreaceae, 8 in addition to the 
papers already cited in my previous notes on this subject, make it unneces- 
sary to enlarge further on the existence of intrafascicular cambium in the 
Liliiflorae ; I will now merely mention that I have recently found cambium 
in the bundles of the very young leaf of Rhipogonum album , R. Br., a member 
of a genus which is not included in Mme Gatin-Allorge’s study. But, 
before leaving the Liliiflorae, there are one or two points in connexion with 
the bundles of this Cohort to which I should like to refer. I drew attention 
in 1919 9 to the fact that in the foliar bundles of a number of Monocotyledons 
there is a differentiation of the xylem into (i) protoxylem, (ii) primary 
1 Arber, A. (1917), (1918), (1919). 2 Gatin, V. C. (1920). 
3 Dauphind, A. (1917). 4 Andersson, S. (1888). 6 Lonay, H. (1902). 
6 Chauveaud, G. (1911). 7 Queva, C. (1907). 8 Queva, C. (1894). 
9 Arber, A. (1919). 
[Annals of Botany, Vol. XXXVI. No. CXLII. April, 1922.] 
