Anatomy of the Cone and Fertile Stan of Equiselunt. 703 
EXPLANATION OF PLATES LXIV AND LXV. 
Illustrating Lady Isabel Browne’s paper on the Anatomy of the Cone of Equisetum. 
Fig. 1. Transverse section of the stele of a node of E. arvense , showing the bundles united into 
a ring of xylem and phloem. At the upper side of the photograph the ring is not quite complete ; 
the complete ring of xylem persists a little way below and above the departure of the traces ; on one 
side the section passes through a region where the ring of xylem is complete and no traces are 
departing, x 80. 
Fig. 2. Transverse section of part of the stele at the node of a cone of E. arvense. This photo- 
graph illustrates a case in which the traces depart from strands unusually far apart, and there is 
no formation of a ring or bands of xylem. A trace has just departed from a bundle on the reader’s 
left hand, x 80. 
Fig. 3. Transverse section of part of the stele of the internode of the cone of E. arvense. The 
separate bundles are wider, compared to the parenchyma between them, than in E. palustre or in 
E. limosum. x 80. 
Fig. 4. Tangential longitudinal section through part of the cone of E. arvense. This photo- 
graph illustrates the fact that sometimes the strands alternate at the nodes and sometimes they pass 
uninterruptedly through the nodes, x 22. 
Fig. 5. Transverse section of part of the stele of the axis at the insertion of an abnormal annulus 
in E. arvense. Some of the bundles are in the condition typical of the vegetative internode, while 
two masses of reticulate tracheides and the phloem outside them are passing in opposite directions 
and obliquely round the stele, x 65. 
Fig. 6. Transverse section of the stele at the node of the cone of E. palustre. Two of the 
trace-bearing bundles are united, the others are separate though more approximated and larger 
than in the internode. In this species the strands often become united just above the node by their 
forking, and by the fusion of adjacent forks of neighbouring bundles ; all the bundles do not give off 
traces at exactly the same level, so that the photograph of any single section does not show as much 
xylem as is present in the nodal region, x 65. 
Fig. 7. Transverse section of part of the stele of the internode of E. palustre , showing small 
bundles, x 80. 
Fig. 8. Transverse section of part of the stele of the internode of a large cone of E. limosum. 
x 80. 
Fig. 9. Transverse section of the stele in a small young cone of E. palustre, var. polystachion, 
showing ring of separate bundles, x 80. 
Fig. 10. Transverse section of stele just above the annulus of small young cone of E. palustre, 
var. polystachion , showing the formation of bands of xylem owing to fusion of bundles, unconnected 
with the departure of any traces, x 80. 
Fig. 11. Transverse section of the stele at the node of a small young cone of E. palustre , var. 
polystachion ; as in the more typical specimens, some bundles are isolated and others fused, x 80. 
Fig. 12. Transverse section of the stele of large, mature cone of E. limosum. Some of the 
bundles are giving off traces, but owing to the irregularity of insertion of the sporangiophores, 
others have done so lower down or will do so higher up. Some of the bundles have already forked 
above the departure of traces and the branches have begun diverging, but have not yet fused with 
their neighbours (e. g. the two small bundles in the middle of the photograph on the reader’s left) ; 
this accounts for the slight increase in number of the bundles ; in the internode below there were 
eighteen, and this is. also the number of the traces, x 55. 
