Notes on Recent Literature. 
189 
accurate study of the only known example of Adelophyton Jutieri 
have, so far as the reviewer is aware, passed unnoticed in English 
botanical literature. 
The fossil in question is a fragment of a stem; its phyllotaxy 
is tj 8 , and in a transverse section we find twenty-one foliar woody 
strands that have penetrated inwards for varying distances; the 
most internal one, i.e. that derived from the uppermost leaf of the 
cycle, has fused with a small circular internal strand. This internal 
strand is the only other wood found in the stem besides that of the 
decurrent traces. If we follow the sequence of events from below 
upwards we shall see that the internal strand describes a spiral 
corresponding to the phyllotaxy and appears to give rise suc¬ 
cessively to all the leaf traces. M. Bertrand speaks of this internal 
strand as a sympodium, formed by the fusion and prolongation of 
successive traces with a small compensation strand. Further he 
speaks of this internal strand as going to encounter the incoming 
woody strands, referring presumably to its spiral course ; but from 
his figures it is clear that the wood of the incoming trace also 
passes inwards, separating from its mass of phloem, which, re¬ 
maining more towards the periphery of the stem, forms with the 
other phloem masses a series of anatomosing strands similar to 
those found in recent Ferns. Moreover M. Bertrand repeatedly 
emphasizes the unique independence of phloem and xylem systems 
in this plant; he points out that though the two systems come into 
connection for the formation of traces, their independence could 
not well be greater. “ It is,” he says, “ in fact absolutely necessary 
that the central sympodium should send a woody strand to each 
frond; in order to pass out this strand must make a hole in the 
phloem-tube ; and it is almost obligatory that this opening should 
be produced precisely by the departure of the phloem of the same 
leaf-trace;. so that it is impossible to imagine a greater 
independence of the two systems without at the same time pro¬ 
ducing inextricable disorder in the arrangement of the stem.” 
As regards the histology of this remarkable plant the wood of 
the leaf-trace consists of a horse-shoe-shaped mass, normally 
oriented, i.e. with the concavity facing inwards, with five to seven 
groups of scalariform vessels on the inner edge ; there is some 
evidence to show that as the trace passed out into the leaf it became 
concentric ; though the course of the phloem strands is less peculiar 
than that of the xylem strands the protophloem is unique in that, 
according to M. Bertrand, it is distinctly central. 
