OF THE STIPES OF FERNS. 379 
spread-eagle of the common Pteris,—I may mention, for the in- 
formation of those who have not paid special attention to this 
subject, that this character was employed to a considerable extent, 
and was apparently much relied on, by Presl, in his ‘Tentamen 
Pteridographiz,’ published in 1836, and has since attracted the 
attention of other authorities on Ferns,—for example, M. Fée in 
his ‘Genera Filicum’ (1851), where numerous figures are given. 
As a distinguishing character I think I may venture to say it is 
unsatisfactory, at least this is my experience ; for not only does the 
condition of the vascular bundles vary at different elevations in 
the same stipes, but different stipes from the same crown present 
different conditions, the fact being that the most vigorous fronds 
are furnished with a greater number of these bundles, whilst the 
smaller fronds have fewer. I may mention, in illustration of the 
unsatisfactory nature of conclusions drawn from this character, 
a case which occurred during the last summer. <A correspon- 
dent, who, like me, is firmly convinced of the absolute distinctness 
of Lastrea spinulosa and L. dilatata, obligingly sent me sketches 
of sections of the stipes, which he thought would probably fur- 
nish a more positive means of distinction than the characters 
now employed, in which conclusion he was apparently justified 
by having found in the plants he examined, that the former of 
these had only three bundles, whilst the latter had five bundles, 
somewhat differently arranged. The very first frond of L. spi- 
_nulosa however which I examined after the receipt of this com- 
munication, showed the number and arrangement which had 
been pointed out as characteristic of L. dilatata ; this happening, 
no doubt, in consequence of a vigorous frond having been se- 
lected for examination; for smaller fronds from the same root 
gave the three bundles which had been supposed to be character- 
istic of the species under examination. Similar results are fami- 
liar to those who have been accustomed to trace out distinctive 
characters in living plants. Hence I attach no value whatever | 
to the statements and inferences in those writings relating to 
Ferns im general where this character has been employed, and 
where it has chiefly or entirely been drawn from an examination 
of foreign specimens (often mere fragments) in the herbarium ; 
for unless one could be certain at what point of the stipes the 
examination had been made, and what was the comparative de- 
sree of vigour in the specimen examined, it is evident from the 
