ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
193 
BOTANY. 
(Under the direction of A. B. Rendle, M.A., D.Sc., F.R.S., F.L.S.) 
GENERAL, 
Including- the Anatomy and Physiology of Seed Plants. 
Structure and Development. 
Vegetative. 
Cambium in Root of Acorns Calamus. — A. Maillefer (Bull. 
Soc. Vaud. Sc. Natur., 1920, 53, 77-9, 1 fig.). A short study of the 
anatomy of the root of Acorus Calamus , with special reference to the 
Central part of a transverse section of the root of Acorus Calamus. 
e, endodermis ; b, vascular bundle ; l, phloem bordered towards the 
interior by a layer of cambium ; p, pericycle. 
significance of a layer of active cambium between the xylem and phloem. 
This layer plays an insignificant part in secondary increase of thickness, 
since it only gives rise to a few cells of phloem-parenchyma, and never 
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