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II. Contributions to the Dec wmm of the CYCADACEE. 
By W. C. WonsP&ELL, F.L.S. 
(Plates 15 & 16.) 
Read 15th November, 1900. 
FURTHER material having recently come to my hands the investigation of which 
afforded results of an importance which could not be overlooked, and, moreover, fresh 
insight into the significance of the Cycadean structure as a whole having demonstrated 
to me the far-reaching importance, as I conceived it to be, of certain facts whose value 
when they were, a few years ago, cursorily observed was inadequately estimated, induce 
me to bring together the scattered data in order to show their important bearing upon 
the problem as to the structural affinities of the Cycadacee. 
The present investigations include that of young plants of the rare Queensland Cycad 
Bowenia, which exhibit in their stem-structure an extrafascicular vascular system 
similar to that of Cycas, Encephalurtos, and Macrozamia. Other features in this genus 
are the concentric vascular strands, of purely physiological significance, scattered 
throughout the swollen parenehymatous tissue of the stem of one specimen, and the 
concentric type of structure of the cotyledonary bundles. Macrozamia Denisonii, 
F. Muell., with its tap-root preserved, exhibits in the region of the primary node extra- 
fascicular concentric strands which are the homologues and earliest beginnings of the 
Jater-formed extrafascicular vascular zones in the same position. 
Sections through the primary node of Cycas Seemanni, Al. Br., show rudimentary 
remnants of an ancient Medullosean character in the form of inversely-orientated vascular 
strands scattered here and there on the inner or ventral side of the extrafascicular zones. 
In one section the first extrafascicular zone is represented entirely by concentric strands. 
In the male and female cones of Encephalartos the structure of the peduncle is 
essentially that of the primary node of the vegetative stem, exhibiting extrafascicular 
concentric, or partially concentric, strands with loosely-compacted segments. A very 
interesting ancestral Medullosean character is seen in the sporophyll-bearing axial 
region of the male cones of Ceratozamia latifolia, Miq., and C. mexicana, Brongn., in 
the form of concentric, or remnants of concentric, strands coustituting a ring, or vestige 
of such, within the vascular cylinder. The vegetative stems of Zamia and Dioon edule, 
which were investigated, offer nothing in their structure worthy of remark. 
BowENIA sPECTABILIS, Hook. 
Young Seedling. 
The excellent description by Mr. H. H. W. Pearson * of the structure of seedlings of 
this plant of 7 months’ growth is so exhaustive, that it removes the necessity for me todo ` 
* Pearson: “ Anatomy of the Seedling of Bowenia spectabilis, Hook. f.,” Annals of Botany; vol. xii. 1898. 
SECOND SERIES.— BOTANY, VOL. VI. Q 
