477 
Vascular System of Matonia pectinata. 
older specimens, left no doubt of their identity. The rarity of the young 
plants of this species compared with the comparative abundance of those 
of Gleichenia linearis and Dipteris conjugata in similar situations was 
rather striking. Neither Dr. Lang nor I succeeded in finding any 
specimens with the prothallus attached, in spite of continued hunting. 
In addition to the six young plants, I subsequently found some plants 
with thin rhizomes and small comparatively simple fronds growing in the 
deep shade of a rock-cleft. These were evidently much older than the 
oldest of the six, but had been starved owing to want of light and perhaps 
also to lack of soil. 
The specimens thus obtained form a fairly good series, both as regards 
the gradually increasing complication in the form of the frond, and also, 
as we shall see presently, in vascular structure. 
During my stay on Ophir I naturally took the opportunity of laying 
in a good stock of material of the adult plant, and after my return to 
England I sent, at Prof. Weiss’s request, a few nodes preserved in spirit to 
the Owens College, Manchester. In this material Miss Wigglesworth, a pupil 
of Prof. Weiss, discovered a distinctly more complicated type of structure 
than that described by Mr. Seward, a type with three concentric amphi- 
phloic siphonostelic cylinders in the rhizome 1 . It thereupon seemed 
desirable to work through the whole of my stock of material, and 
Miss Lulham undertook this laborious task. 
The results of the investigation, together with those obtained from 
the young plants 2 , are now presented. The considerable delay in publi- 
cation has been due to a variety of causes, not the least being the lengthy 
character of the work. No less than fifty nodes have been examined 
from the adult plants alone, several thousand sections have been cut, and 
numerous wax models made. It is hoped that the fairly complete account, 
which we are now able to give, of the progressive complication in the 
vascular structure of this unique type, may be a sufficient justification. 
A. G. TANSLEY. 
The Morphology of the Leaf. 
A comparison of the fronds borne by the different young plants (Plate 
XXXI, Figs. i-8) shows considerable variety of form, and, in the larger 
fronds at least, a mixture of the dichotomous and monopodial types of 
branching. There is, however, as we shall see, good reason to believe that 
dichotomy is the primary method. 
Plant A (Fig. i) has one tiny frond which is simply bifid. The 
larger frond is trifid, and might be considered to consist of a central 
1 Grace Wigglesworth, New Phytologist, vol. i, 1902, p. 157. 
2 I am indebted lo my wife and to Miss E. N. Thomas for preparing sections of the six young 
plants. 
