BIG, 
/ 
A 
X. On the Anatomy of the Roots of Palms. By Eric DRABBIE, D.Se., F.L.S., 
Lecturer on Botany, St. Thomas's Hospital, London. 
(Plates 48-51 and 22 text-figures.) f 
Read 3rd December, 1903. 
INTRODUCTION. 
H. VON MOHL, in 1845, published an admirable account of the roots of Palms in 
his work ‘De Structura Palmarum’ (1). He described the typical arrangement of 
the tissues and observed that the central cylinder of the adventitious roots can be traced 
internally as a series of strands of xylem and phloem which penetrate deeply into the 
central cylinder of the stem. He also described and figured the cylinder of a large root 
of Iriartia, of which the outline is not circular, but deeply lobed in a stellate manner, 
the ends of the rays being usually bilobed. At the same time he gave an account of 
the medullary strands of fibrous or sclerenchymatous tissue, containing vessels and in 
some cases phloem also. He further noted that the fibrous ring in which are embedded 
the xylem- and phloem-bundles is often divided up into wedge-shaped masses by radial 
extensions of the medullary parenchyma. 
The convergence internally of the xylem-bundles in pairs forming V’s, between the 
arms of which lie phloem-groups, was described in .Diplothemiwm maritimum and 
Chamedorea elegans. 
Karsten (2), in 1847, added to our knowledge of the anatomy of palms in a 
magnificently illustrated paper, in which a figure of the origin of adventitious roots is 
given showing some indication of the internally penetrating vascular strands in Zriartia 
premorsa, Kl., and a figure of the lobed cylinder in the same species. A longitudinal 
figure of the apex seems to show that he found a single undifferentiated apical 
meristem. 
Naegeli, 1858 (3), Russow, 1875 (4), and Falkenberg, 1876 (5), contributed incidentally 
to our knowledge of the histological structure of palm-roots, and De Bary, 1877 (6), 
summarized the work of all preceding investigators. 
Van Tieghem, 1870 (7), in his first monograph on ‘ La symétrie de structure dans les 
Plantes vasculaires, (i) La Racine,’ describes the roots of Phenix dactylifera and 
Seaforthia elegans. 
Olivier, 1880 (8), cites Flahault’s work on the primary root-apex in Phenix dactylifera, 
describing it as possessing a well-defined plerome-initial group and a second group 
common to the other layers. Olivier also describes and figures a zone of sclerenchyma 
in the internal portion of the parenchymatous cortex, immediately external to the 
endodermis. 
SECOND SERIES.—BOTANY, VOL. VI. 3Q 
