xvi Obituary , — David Thomas Gwynne- Vaughan, 
under the influence of the Theory of Descent — the comparative anatomy of 
the Darwinian period at its best. 1 
Going back to the year 1901, there is a Note ‘On the Nature of the 
Stele in Equisetum ’ (1901. 2), a subject on which he never published in full, 
though he continued to give it much attention. He regarded the vascular 
bundle of Equisetum as a compound structure — ‘ of the three strands of 
xylem present in each bundle of the internode, the carinal strand alone 
passes out at the node as a leaf-trace \ ‘ So the xylem of the so-called 
vascular bundle of Equisetum consists of three strands, two of which are 
lateral and cauline, while the median, or carinal, strand is common to both 
stem and leaf. The fact that only a small portion passes out as a leaf-trace, 
and not the bundle as a whole, constitutes an essential point of difference 
between it and the bundle of a Phanerogam.’ 
He further pointed out that the lateral xylem-strands in E. giganteum 
gave a strong impression of centripetal development. He compared the 
stele of Equisetum with the protostele of Sphenophyllum , and with the 
various degrees of medullation found in the Lepidodendreae, and suggested 
that the lateral xylem-strands in the recent genus ‘ may perhaps be taken 
to represent the last remnants of a primitive central mass ’. His idea was 
that the lateral strands in Equisetum might correspond to the prominent 
points of the primary xylem in Sigillaria , in the hollows between which the 
protoxylems lie. 
This Note must not be taken as representing Gwynne-Vaughan’s final 
view of the morphology of the stem in Equisetum, Judging from letters 
of his (1912), and from manuscripts he left, it appears that while he always 
maintained his view of the triple nature of the bundle, and of the essentially 
protostelic character of the vascular system, he was inclined to give up the 
centripetal development of the lateral strands, and to admit the possible 
occurrence of leaf-gaps in certain cases. The whole question is an inter- 
esting one, and it is much to be regretted that Gwynne-Vaughan’s mature 
views were never fully recorded. 
In a Note (1902) ‘ On an Unexplained Point in the Anatomy of Helmin- 
thostcichys Zeylanica\ Gwynne-Vaughan described for the first time the 
curious canals which lead down through the cortex almost to the stele, one 
in front of each leaf. He thought it ‘ possible that they represent the last 
indications of vestigial axillary buds ’, a suggestion which has since been 
confirmed by the work of his friend Lang. 2 
We owe to Gwynne-Vaughan (1905. 1) the first description of the 
anatomy of the new genus of Marattiaceae, Archangiopteris , discovered by 
Dr. Henry in China. The structure was compared with that of Kaidfussia , 
1 The British Association Note (1901. 3) is preliminary to the paper just considered. 
2 W. H. Lang, Studies in the Morphology and Anatomy of the Ophioglossaceae. Ill, p. 14. 
Ann. of Bot., January, 1915, vol. xxix. 
