Scott. — On Peduncle of Cycctdaceae. 413 
been observed, are so widely scattered throughout the Order, 
that other examples will undoubtedly be added on further 
investigation. 
Conclusion. 
The most important result of these observations has been 
to establish the fact that the mesarch type of vascular bundle, 
hitherto believed to be limited to the leaf in recent Cyca- 
daceae, also occurs in certain axial organs, namely in the 
peduncles of Stangeria , Bowenia , and some species of Zamia 
and Ceratozamia. Count Solms-Laubach, as the result of his 
work on the course of the vascular bundles of Cycads, came 
to the conclusion that in these plants the peduncle shows 
a primitive organization, as compared with the vegetative 
stem ; he says : ‘ Sehr merkwiirdig aber ist die Art und 
Weise, wie an einem und demselben Spross unter plotzlicher 
Verjiingung des Pleromkorpers der complicirte vegetative 
Spurverlauf ganz unvermittelt in den einfachen der Bliithe 
tiberspringt. Dass dieser letztere eine Reliquie ur alter Organisa- 
tion 1 , dass er den gemeinsamen Vorfahren der Cycadeen und 
Bennettiteen allgemein eigen gewesen sein wird, dass der 
vegetative Spurverlauf, wie er jetzt bei ersterer Gruppe 
vorliegt, eine im Laufe der Zeit erworbene Eigenschaft 
darstellt, die den Gang der Entwicklung in der Richtung vom 
Einfachen zum Complicirten uns vor Augen fuhrt, scheint mir 
eine sehr nahe liegende Annahme zu sein/ 
My observations on the structure of the vascular bundles 
in the peduncle completely confirm Count Solms’ conclusions, 
drawn from their arrangement. In the presence of centripetal 
wood, so well marked in the peduncle of Stangeria , and 
evident, though less conspicuous, in other cases, we have the 
same character, in a reduced form, which is presented by 
the vegetative stem of the fossil plants Lyginodendron and 
Poroxylon , as well as by the Calamopitys Saturni of Unger. 
The italics are my own. 
F f 2 
