Anatomy of the Cone and Fertile Stem of Equiseium. 693 
that in Cone B we are dealing merely with a case of early closure of certain 
meshes, and parallel cases of early closure are by no means rare in the cone 
of this species. But in Cone C such an explanation would not account for 
the fact that the traces of the first whorl seem in some cases to lie above and 
between the strands of the internode rather than above and in the middle 
of them ; in this cone, too, one fresh mesh originates above the annulus 
and very much at the level at which some of the other meshes are closed. 
To return to E. palustre y in which the percentage of closure and of 
origin of meshes in the annular region is highest and in which the nodal 
appearance of this region in longitudinal reconstruction is therefore most 
striking, we find that in Cone A six out of seven, in Cone B four out of 
eight, and in Cone D four out of six meshes are closed in the neighbourhood 
of the insertion of the annulus. Notwithstanding the persistence of bands 
of xylem into the internode above the annulus, four fresh meshes originated 
above* the annulus in Cone A, three in Cone B, and three in Cone D. 
Cone C was exceptional ; though there were eight strands below the 
annulus and nine sporangiophores in the second fertile whorl, the basal 
whorl of the cone consisted of but three sporangiophores. The increase in 
number of trace-bearing strands to nine in the second fertile whorl is due 
to the fact that above the lowest whorl of the cone a band consisting of 
three strands (that with two other single strands gave off no traces at this 
node) breaks up into four strands ; thus the increase in the number of 
strands takes place between the first and second whorls of the cone and not 
between the annulus and the lowest whorl. Nevertheless, six out of eight 
meshes were closed and four originated in the neighbourhood of the 
annulus. It is curious that none of the fourteen meshes originating above 
the annuli of the cones of E. palnstre examined were of the first order. It 
must, however, be remembered that meshes of the first order are much 
rarer in the cones of E. palustre than in those of E. arvense . 
In E. limosum the indications of the nodal structure of the axis at the 
insertion of the annulus are less marked ; in Cone A we notice one case of 
the origin of a mesh above the annulus. In Cone B there are four meshes 
which I interpret as arising above the annulus ; like the mesh in Cone A 
they are of the second and higher orders. The mesh below the second 
trace of the lowest whorl of this cone appears to be closed in the region of 
insertion of the annulus and markedly below the level of the basal whorl ; 
this is true, too, of the meshes above the twelfth and thirteenth leaf- traces ; 
but this cone is still so young and has elongated so little that it is exceed- 
ingly doubtful if we are dealing with bands of xylem persisting through an 
unelongated supra-annular internode or with early closure of a mesh before 
the first fertile node. Cone C of this species showed two clear cases of 
meshes originating above the annulus. This tendency of meshes to be 
closed slightly above a node was noticed also in various cones (cf. pp. 680-1). 
