Notes. 
170 
Phascaceae are but little further developed than those of Buxbaumia. 
But what I wish to point out here is that the prothallium of Schizaea 
is at just the same stage of evolution as the hypothetical Alga postu- 
lated by Goebel as the ancestor of the Mosses. 
Many other points call for consideration, but their discussion would 
go beyond the scope of such a preliminary account as the present, and 
must be deferred. I hope, however, to shortly offer a further account 
of the present prothallium as well as those of other species of Schizaea. 
It will be seen that, whatever interpretation we place upon it, the 
prothallium of Schizaea is a highly interesting form. But does not 
the weight of evidence justify its recognition as a relatively primitive 
type, which probably represents the character of the common Alga- 
like ancestor of both Ferns and Bryophytes more nearly than any 
plant hitherto described ? 
A. P. W. THOMAS. 
University College, Auckland, N. Z. 
ON AN UNEXPLAINED POINT IN THE ANATOMY OF 
HELMXNTHOSTACHYS ZEYLANICA.— It has not been, I 
believe, hitherto recorded that in Helminthostachys zeylanica there 
are a number of small passages or canals running through the 
cortex from the neighbourhood of the stele to the external surface 
of the rhizome. These canals bear a definite relation to the leaf- 
insertion : one being situated in front of each leaf, opening out on to 
the surface immediately above the insertion of the ‘ stipule ' of 
the leaf to which it belongs, not in the median line of the rhizome 
but well down towards the under side. The passage may, in fact, 
be regarded as a backward prolongation into the cortex of the space 
that lies between the ‘ stipule * and the stem as a narrow canal 
running right up to the stele. 
The presence of these canals exercises a considerable influence 
upon the stele, and occasions certain modifications in structure which, 
I think, may best be explained by describing the manner of the 
departure of the leaf-trace, which the woodcut is intended to illus- 
trate. The figure A is a diagrammatic longitudinal section of the 
stele in the neighbourhood of the leaf-gap, while B and C represent 
transverse sections taken at the levels aa and bb respectively. The 
xylem is represented by dark shading, the phloem by light, the 
parenchymatous tissue being left unshaded ; the dotted line indicates 
