Studies on Intrafascicular Cambium in Monocotyledons 
(III and IV ). 1 
BY 
AGNES ARBER, D.Sc., F.L.S., 
Fellow of Newnham College , Cambridge. 
With seven Figures in the Text. 
Contents. 
PAGE 
III. On the Development of the Foliar Bundles in Veratrum album L. . . 459 
IV. New Records of the Occurrence of Intrafascicular Cambium . . . 462 
Methods 464 
Summary 464 
Acknowledgements 465 
III. On the Development of the Foliar Bundles in 
Veratrum album l. 
T HE part of the vegetative, shoot of Veratrttm album L. visible above 
ground during, the spring and summer appears at first glance to con- 
sist of an erect axis bearing spirally arranged sessile leaves. But on closer 
examination the ‘ axis ’ proves to be merely the extremely long cylindrical 
leaf-sheaths, which successively enclose one another, the true stem being 
subterranean. The life and growth of the leaves are markedly protracted. 
If the plant be examined towards the end of August, when — at least in 
plants cultivated in this country — the leaves of the current year are fully 
mature and already beginning to fade, next year’s leaves will be found, 
beneath the level of the ground, enclosed in a flask-like dilatation of this 
year’s leaf-sheaths. The outermost of next year’s leaves take the form of 
closed conical scales, and surround the normal foliage leaves with their short 
sheaths and delicately plicate blades. 
In the mature leaves, gathered towards the end of July, each of the 
main bundles of the lamina, as seen in transverse section, is surrounded by 
1 These studies form a continuation of : — 
I. Arber, A. (1917) : On the Occurrence of Intrafascicular Cambium in Monocotyledons. 
Ann. Bot., xxxi, p. 41. 
II. Arber, A. (1918) : Further Notes on Intrafascicular Cambium in MonQcotyledons. Ann. 
Bot., xxxii, p. 87. 
[Armais of Botany, Vol. XXXIII. No. CXXXII. October, igig. 
