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the Sporophylls of the Cycadaceae. 
fugal and an entire absence of centripetal xylem. They 
arise from the branching of three bundles (which really 
represent two, of which one has undergone premature 
division) which enter the sporophyll from the axis of the 
cone, these three originating in the cortex from the single 
bundle which leaves the central cylinder. Owing to this 
premature division of one of the bundles entering the sporo- 
phyll, there are at first a larger number of bundles on one 
side of the organ than on the other. 
In a rather young male sporophyll of M. spiralis , Miq., 
there are about nine bundles in the stalk. 
Female Sporophyll. This is one of the large types of 
sporophyll. Owing to the fact that the material at my 
disposal was dead and withered, the arrangement of the 
bundles in the stalk could not be ascertained, as the sections 
broke up into small fragments. The strands appear to be 
of the same type, in form and structure, as those in the 
female sporophyll of Encephalartos , as they possess a large 
amount of centrifugal and also a small but well-marked 
quantity of centripetal xylem. In the lamina some of the 
bundles are a good size, the centrifugal and centripetal 
parts of the xylem being of about equal development, though 
the former seems to stain rather more sharply than the 
latter. 
Zamia latifolia, Lodd. 
Male Sporophyll. In the lower part of the stalk are three 
bundles with the typical centrifugal and no centripetal xylem. 
A little higher these divide up into a rather larger number, 
of which one from each side is seen to pass off to the dorsal 
side of the sporophyll. One of the bundles in this region 
show a good example of primary centrifugal xylem ; it has 
a single, minute, flattened tracheide of secondary centrifugal 
xylem separated from the other portion of this tissue by 
a layer or two of roundish parenchyma-cells; next, towards 
the ventral side succeeds a row of four or five tracheides, 
very well-defined, and with brightly-coloured walls, and then 
