TRANSACTIONS OF SECTION K. 779 
the leaf-trace of Filicine is built on the same plan as that of Anachoropteris, 
Botryopteris, Zygopteris—that it had the same elementary pieces, which unite in- 
the same way. This study indicates the special characters of the three types of 
traces and the inversion of the curvature of the chain in the leaves, 
Anachoropteris shows in the leaf-trace bipolar bundles united pole to pole, 
and breaches in the centre of figure. The inverse curvature of the chain in 
Anachoropteris was indicated by Corda. It is confirmed by sections taken in the 
ramifications of the petiole, and by the study of specimens in which the fronds 
still surround the sézpe which bears them. The study of the last specimens was 
made by M. Stenzel. 
The leaf-trace in Anachoropteris is a binary chain, the curvature of which is 
inverted. It has, consequently, two anterior double poles and wings which turn 
backward. When these wings are long they are prolonged into spirals, but they 
do not meet and the chain remains open. 
The emission of lateral pieces (veins or petiolar traces) is always effected by 
the separation of elosed inverse divergeant ‘a wil ouvert ’—that is to say, with an 
ingrowth of phloem into the centre; or ‘@ etl plein, where no such ingrowth 
occurs, 
This mode of emission is comparable with that one of Aspleniwm nidus, and 
with that of Microlepia, The lateral piece takes only a little part of the half 
anterior arc. The lateral emissions come off between the interior face of the half- 
anterior are and the anterior face of the leaves. 
In the upper ramifications of the frond the leaf-trace is reduced to a closed 
inverse divergeant retaining the character of its curvature even when much 
reduced. 
In the leaf-trace of the Botryopteris type the chain of the petiole may be 
divided into (1) a trunk, (2) a receptive chain on either side, which receives 
(8) the branch chains (or veins). 
The characters of traces of the Botryopteris type are a binary chain of inverse 
curvature, the posterior are of which is much reduced and may disappear. The 
anterior half-ares are large; they may join posteriorly, and so close the chain. 
The end bundle, F™®, touches on a large area the bundle of the posterior 
arc, a 
The branches always come off from the beginning of the anterior half-arcs, 
The largest phloem elements (sieve tubes) oceur on the flanks of the anterior 
bundle and in front of the posterior bundle. The surrounding phloem morpho- 
logically is an internal phloem. The morphological external phloem is crowded 
out. All the branches given off on the same side are reduced to a closed inverse 
divergeant ‘a cil plein,’ and unite to form a receptive chain whose poles are 
external, The two receptive chains of right and left unite together in front of the 
point where the trunk chain is closed. 
Here is a remarkable development of the anterior face, which begins to extend 
round the far side. The trace retains the same characters even in the superior 
ramifications, and this is found in the whole series, from Botryopteris forensis to 
Rachiopteris tridentata. 
The characters of the Zygopteris trace, taken in its most differentiated type, 
say, Zygopteris Lacatti’, are a quatenary unopened chain of inverse curvature, 
whose margins (points of ramification) are occupied by a complete bundle. 
The anterior bundle, F™*, touches widely the posterior bundle, F™®, which is 
nearer to the anterior face, The emissions occur in four symmetrical spots. There 
are four large receptive lobes, constricted at the base, where they join a median 
apolar piece. 
The emission is effected by a closed inverse divergeant ‘a il plein. The 
two emissions of the same side may unite, at least for a short distance, into a 
single chain of apparently direct curvature. Two or four lines of lateral ramifica- 
tion are possible. They are always formed of closed inverse divergeants associated 
into a chain of direct curvature. The receptive lobes disappear in the forms 
Zygopteris duplex, Dineuron pteroides. They become receptive prolongations in 
Diplolabis esnostensis, and in the species from Zygopteris insignis to Zygopteris 
