22 I 
the Sporophylls of the Cycadaceae. 
development of the centrifugal and centripetal xylem occurs 
as in previous cases. 
Of the four normally orientated bundles in the stalk, the 
two lateral ones which supply the sporangia are considerably 
the largest. One or two small elements of centripetal xylem 
may occur in any of the four bundles, but are nearly always 
present in the large lateral ones. From each of these latter, 
as they enter the lamina, two bundles branch off to the 
sporangium ; and each of these, immediately before entering 
the latter, may divide up into two or three. In transverse 
section of the part immediately below the insertion of the 
sporangium, one of the two bundles is seen to be divided into 
three. 
Scale Leaves and Barren Sporophylls. At the base of the 
male cone are a number of scale leaves similar to those in 
Stangeria. They contain a row of many bundles with 
endarch structure and very small in size ; a few bundles 
also occur on the ventral side of this row and appear to be 
normally orientated. Immediately below the compactly- 
arranged sporophylls of the male, are two or three elongated, 
barren sporophylls (Fig. 13). In the case of one cone, each 
barren sporophyll contains, in its lower portion or stalk, a row 
of four or five bundles, of which the two end ones of the row 
are concentric in structure (Fig. 14), one of these being very 
small, the other of normal size. The intermediate bundles 
are rather larger in size than those of the fertile organ, this 
being due, possibly, to the smaller number of the former ; 
their structure is similar, the centrifugal xylem being sharply 
defined and the phloem well developed ; in the upper part, 
or lamina, the smallest concentric bundle dies out, while the 
larger one assumes a collateral structure ; while, as regards 
the other bundles, a similar change in their structure takes 
place as in the fertile sporophyll. 
DlOON EDULE, Lindl. 
Male Sporophyll. In the narrow stalk is a single row of 
bundles. All are of quite small size and of nearly equal 
