254 BOTANICAL GAZETTE [OCTOBER 
one whose brilliant investigations on the anatomy of the cycadean 
peduncle have put the whole subject of the affinities of the cycads 
with the lower extinct gymnosperms in a new light. Dr. Scort 
from his discovery of centripetal xylem in the peduncles of the 
reproductive axes of certain living cycads reached the conclusion 
that their ancestors with strong probability possessed similar bun- 
dles in their vegetative stem. This condition is in fact realized 
in certain of the Pteridospermeae, particularly in Lyginodendron, 
which Dr. Scorr regards as a probable ancestor of the cycads. 
There can be no question that Archeocalamites and Calamites are 
very much more nearly related to Equisetum than is Lygindodendron 
or any similar form to the living cycads. It follows that the reproduc- 
tive axis of Equisetum is much more likely to perpetuate the ances- 
tral characters of its stock than is the cycadean cone. It appears to 
have been shown above beyond any doubt that the equisetaceous 
strobilus perpetuates both the non-alternating strands and the com- 
plete absence of foliar gaps of the oldest calamitean forms. In - 
light of these facts there can be no reasonable doubt that the peculiar 
anatomical relations of the vegetative foliar traces of Equisetum ate 
likewise persistently retained indications of the ancestral condition, 
for although the shifting of the internodal strands in the course of 
evolution has caused them to subtend the gaps between the strands of 
the next upper internodes, they still leave the central cylinder without 
giving rise to true foliar lacunae, and are moreover separated from 
their apparent gaps by the whole depth of the supranodal wood. 
Collateral evidence of the correctness of this view of an even more 
cogent kind has been discovered, but is reserved for a subsequent 
communication. 
The older members of the equisetal alliance may now ne a 
sidered. Wess in one of his superb and classic monographs se! n 
Carboniferous Calamites'+ has published a number of illustrations 
of calamitean cones. On ls. x and 2 are figures of the genus sue 
annularia, which show clearly the phenomenon of no peer” 
at the nodes of the cone. Pls. 3 and 4 show the same arse di 
af cam 
in the well-known genus Calamostachys. In pl. 9 a simi 
. ‘4 rte Vv. 
‘4 Steinhohlen-Calimarien, Atlas zu denAbhandlungen Gelog. Specialka 
Preussen 21; Berlin. 1871. 
