262 Browne—A Second Contribution to our Knowledge of ihe 
2. The cones with wider steles have, on the whole, a more reduced 
vascular system, presumably because the reduction in width of the stele 
has not kept pace with the reduction in the number of elements lignified. 
3. The reduction of xylem is manifested, as in the other species 
studied, by the persistence of parenchymatous meshes upwards, and by 
their extension, phylogenetically speaking, laterally and downwards. 
This leads to great irregularities, especially in the larger cones; in the 
latter these irregularities take the form of local duplication of the whorls, 
and in extreme cases of the development of pseudo-whorls. 
4. Owing to the persistence of meshes on either side of a strand 
through more than two internodes, cases of superposition of traces at their 
origin are relatively common, especially in the cones with relatively more 
reduced vascular system. 
5. Another effect of reduction of the vascular system is the presence of 
unlignified parenchymatous cells between the tracheides, and the poor 
lignification of the latter, especially in the lower part of the cone. 
6 . One character, apparently relatively new in the phytogeny, leading 
locally to increase of xylem, is the tendency for two or more strands to 
become united by the production of additional tracheides at a considerable 
distance below the departure of the traces. 
7. Groups of medullary tracheides seem to be not uncommon in the 
cones of this species. 
8. The traces of the lower whorls of sporangiophores often diverge 
downwards ; this is especially common in the mature cones, and is probably 
chiefly due to the pull exerted by reflexed sporangiophores, and to the 
unequal elongation of the inner and peripheral tissues of the axis. Though 
the analogy with Palaeostachya is suggestive, the sporangiophores appear to 
be morphologically distinct in the two genera. The analogy in the course 
of the traces of the sporangiophores of E . maximum and Palaeostachya is 
not a close one, and their downward sweep is probably not due mainly to 
the same causes. 
9. An abnormal branching of the cone is described, as are also 
exceptional cases of the dying out of incoming traces in the cortex. An 
example of abnormal abortive branching of the vegetative part of the 
fertile stem was also met with. 
My thanks are due to Professor F. W. Oliver, F.R.S., in whose laboratory 
the present investigations were carried out, and to Mr. T. G. Hill, B.A., for 
much help and encouragement. I am also indebted to Mr. E. M. Cutting, 
M.A., for handing over to me a considerable amount of material, including 
Cone D. Some of the cones of E maximum studied were kindly supplied 
to University College by Dr. E, N. Thomas. 
