442 Browne . — A Fourth Contribution to our Knowledge of 
E. hyemale a trace has been described passing out from the stele into the 
cortex at the level of the supra-annular anastomoses, though, owing to the 
destruction of the external tissues, it could not be ascertained whether 
these traces died out in the cortex or penetrated the annulus (Browne 
( 3 ). p. 253). The protrusion into the cortex of two tracheides and of 
a few cells resembling phloem and endodermis opposite the insertion of the 
perfectly normal annulus of Cone B of E. sylvaticum may possibly be 
an indication of a vestigial node. The exceptional radial extent and the 
character of the metaxylem in this cone and the small groups of vascular 
cells in the annulus of Cone E of E. debile may also be vestigial nodal 
characters. 
Of the course of the protoxylem Barratt writes : ‘ The protoxylem 
strands from the internode pass without any disjunction to the level at which 
the first sporangiophore traces arise, and hence there is no alternation at the 
so-called “node”. There may be apparent forking of the strands, but this 
is due to the fact that the protoxylem strands in the bundles of the internode 
below are often double, which, separating as they enter the cone, produce 
this appearance of forking. This appearance is emphasized by the dis- 
position of the metaxylem at this region, which is similar to that of the 
so-called nodes from which the sporangiophore traces arise ’ (Barratt, p. 228). 
Of course, if the cases of separation of double protoxylems alluded to 
by Barratt occurred in specimens in which the number of sporangiophores 
was greater than the number of leaves at the last vegetative node little 
significance can be attached to them, since forking of the strands (pre- 
ceded by forking of the protoxylem) is the most natural manner of 
effecting such an increase. Forking of this kind is found in the ordinary 
axes when an increase occurs in the number of members in successive 
whorls (Browne ( 2 ), pp. 257-8). But otherwise the presence of double 
protoxylem strands below the cone would seem to show that the pre- 
paration for the branching of the strand began with the branching, some- 
what lower down, of the protoxylem, a very common procedure in branch- 
ing bundles or meristeles. For, as Barratt points out, there is below 
the annulus an 4 undoubted internode ’ (Barratt, p. 228), and we must 
presume that its strands arose in the usual way, above and between the 
uppermost whorl of leaves. 1 If so, they originated as equivalent bundles, 
each with a single strand of protoxylem, the position of which is marked 
in the internode by a carinal canal. The branchings of the protoxylem, 
about to be described for E. sylvaticum , occur slightly above the insertion of 
1 The bundles of the peduncle — as the axis between the last whorl of leaves and the annulus is 
called — seem typically to arise in exactly the same way as the bundles in the other vegetative 
internodes. I have examined a considerable number of specimens, belonging to seven species, and 
the only real difference that I was able to observe was that in the more reduced specimens of 
E. debile irregularities occurred, owing to the ring of xylem being incomplete at the last vegetative 
node (cf. pp. 440-1). 
