4Q9 
Scott, — On Peduncle of Cycadaceae, 
occurrence, some peduncles not showing them at all So far 
as I have observed they never split into two, as is so often the 
case with the collateral bundles in the cortex. Possibly their 
concentricity is due to this fact, the concentric strand thus 
representing a double bundle, just as occurs sometimes in the 
main ring. As we have already seen, a bundle which is 
collateral below may become concentric higher up ; sometimes 
the change is in the reverse direction. 
In any case these cortical strands are of considerable 
interest, for they constitute, so far as I am aware, the only 
instance hitherto described of Cycadean bundles with 
a primarily concentric structure, retained for a considerable 
distance. They have been observed in quite young peduncles, 
so there can be no doubt that the concentric structure exists 
while the tissues are still in their primary condition 1 . 
The secondary concentric strands, so well known in the 
cortex of Cycas , clearly belong to a different category. 
The evidence for the origin of Cycads from Ferns is now 
overwhelming, Professor Ikeno’s discovery of the multiciliate 
spermatozoids of Cycas completing the proof in the most 
striking manner 2 . Hence one is tempted to look on con- 
centric vascular bundles in a Cycad as a relic of ancestral 
structure. Such an inference must be received with caution, 
but I give the facts for what they are worth. 
Other Anomalies. One or two occasional anomalies remain 
to be noticed. In rare cases a cambium arises in connexion 
with a group of the centripetal xylem, and a little secondary 
phloem is then found on the side toward the pith. I attach 
little or no importance to such isolated abnormalities of 
development, but it may be worth while to point out that 
similar anomalous formations, on a much larger scale, are 
frequent in the fossil Lyginodendron Oldhamium , and are even 
1 Mr. Worsdell has observed other instances of concentric bundles in Cycads, 
which he will describe in a forthcoming communication. 
2 Bot. Centralblatt, Bd. 6 g, Nos. i and 2, 1897 ; Annals of Botany, June 1897. 
Dr. Hirase’s previous discovery of similar spermatozoids in Ginkgo is another 
decided indication that the Gymnosperms generally were derived from the same 
source. 
