(P 
Cet 
ti. 
Il. The Morphology and Anatomy of the DEN of the Genus Lycopodium. 
By CHARLES EDWARD Jones, B.Sc., F.L.S. 
(Plates 3-5.) 
Read 7th April, 1904. 
‘THERE have been in the past very few original communications restricted to an 
investigation of the genus Lycopodium, although between the years 1846 and 1874 
several papers were published which dealt with special features, mainly for the purpose 
of comparison with allied genera, and, as a result, a general but fragmentary conception 
of the structure of Lycopods has been evolved, the substance of which has been 
incorporated into text-books, and occasionally additions have been made when the 
writers have preferred to get the facts first-hand. An explanation of the development 
of the peculiar root-like structure and a comparative description including the 
anatomical features of exotic species have never been published, and it is with the 
intention of providing a fuller comparative account of the stem and its anatomy and 
with the object of elucidating the formation of what may become a very complex 
vascular arrangement that this investigation was undertaken. 
Turning to the early literature concerned with Lycopodium, the paper written by 
Hegelmaier (5) in 1872 stands out pre-eminently as a carefully prepared and reliable 
comparative survey of the characters of the commonest species (Lycopodium clavatum, 
annotinum, alpinum, tnundatum, and Selago). Before Hegelmaier, one or two well-known 
botanists had published results. In 1846 Nägeli (1) was already endeavouring to decipher 
the structure of the growing apices in plants, and for this purpose examined the apex of 
the stem of Lycopodium clavatum. In this paper he refuted the impression which then 
prevailed that the vascular portion consists of one bundle, and pointed out that the 
vascular cylinder consists of a number of vascular strands in accordance with the number 
of protoxylems. He observed that the leaf-traces and the protoxylems differentiate 
simultaneously, and therefore concluded, not, without considering other possibilities, that 
each vascular strand passes off into a leaf-trace.  Náügeli's paper (3) gives an account 
of the root-development, more especially of the branching of the root-system, for 
L. clavatum. There is a figure of a very definite apical cell and a detailed account of 
the formation of root-hairs, but no definite information about the connection of the 
. vascular cylinder in the root with that of the stem. Cramer (2) examined the apex of 
LL. Selago and studied more particularly the leaf-arrangement. He showed that there is 
considerable variation, that sometimes the leaves fall on a spiral—of which the commonest 
is 2/9—and sometimes they are arranged in whorls; also he found that there is no 
relation between the number of leaves and the number of protoxylems. Before 
SECOND SERIES.—BOTANY, VOL. VII, E 
