222 
Review. 
REVIEW. 
A COLONIAL CONTRIBUTION TO OUR KNOWLEDGE 
OF THE GENUS LYCOPODIUM. 
I N 1909 Mr. Holloway (3) contributed to the Transactions of the 
New Zealand Institute a very interesting account of six species 
of Lycopodium. As these Transactions are not within the reach of 
all British botanists it was thought that some account of Mr. 
Holloway’s work and comments on his conclusions might be welcome. 
In the first place Mr. Holloway has made a notable contribution 
to our knowledge of that puzzling organ, the protocorm. A 
protocorm was found in two only of the species he examined: in 
Lycopodium cernuum L. in which its structure was already well 
known and in L. laterale R. Br. In the latter species the protocorm 
is associated—as in the other cases in which it has been found, 
not only in Lycopodium but in Phylloglossum —with a prothallus of 
the Lycopodium cernuum type; the only exception to this generali¬ 
zation is the rudimentary protocorm recorded by Treub for L. 
Phlegmaria. In L. laterale the protocorm as described by Mr. 
Holloway is a comparatively highly developed organ. Instead of 
giving rise relatively early to the stem it elongates laterally to form 
a sort of rhizome bearing numerous protophylls on its dorsal 
surface; in a case figured there are as many as nine of these. 
Further this “ rhizome ” may branch and each branch may give 
rise to a stem, the stem apex being in all cases differentiated by the 
aggregation of the protophylls at a certain point on the dorsal 
surface of the “ rhizome.” The first root arises very late as an 
outgrowth of the latter. 
In Phylloglossum the protocorm or tuber seems to play an even 
more important part than in Lycopodium laterale ; yet the only 
trace of vascular tissue recorded in it is a ring of somewhat degraded 
xylem found by Mr. Wernham (7) in one portion of a single tuber 
of Phylloglossum. This lends great interest to the following passage 
from Mr. Holloway’s paper: “Transverse sections of stems of 
young plants of these species (L. cernuum and L. laterale) at this 
stage show that there is no definite arrangement of the vascular 
tissues, the different xylem and phloem elements preserving no 
constant relative positions. The vascular tissues of the stem lead 
down bodily into the upper region of the protocorm, and, surrounded 
by a slight zone of sclerenchyma, enter the root-like protuberance, 
in the case of L. laterale passing along the dorsal surface of the 
protocorm immediately beneath the epidermis.” It is not quite 
clear from this passage whether the vascular elements passing 
downwards from the stem enter a root-like protuberance in both 
species or only in L. laterale. Presumably this is so only in L. 
laterale as the examples of young protocorms of L. cernuum figured 
show no root-like projections in their upper parts, into which alone 
it is stated that the vascular elements extend. 
