THE ANATOMY OF THE STEM OF THE CALYCANTHACEiE. 
523 
by the abundance of starch grains in its cells. This endodermal layer encircles 
the so-called cortical bundles on the outside, showing clearly that they are pericyclic 
in origin. The pericycle consists of isolated groups of fibres. The cortex divides 
as usual into two layers, the inner containing numerous oleiferous cells. The 
epidermis bears silicified hairs, though not so numerous or so well developed as in 
C. fertilis or C. floridus. 
In longitudinal section the primary xylem consists of annular, spiral, and 
reticulate vessels, and spiral tracheides, while tracheides with uni- or multiseriate 
bordered pits are very frequent in the secondary wood. Scalariform tracheides are 
not common. In the older wood the different varieties of tracheides give place 
almost completely to the peculiar tracheides described in C. floridus and compared 
by Lignier to those found in Taxus. Tyloses are frequent in these tracheides. The 
xylem parenchyma is small in amount and the medullary rays are uniseriate, con- 
sisting of cells containing abundant starch. They may be from twelve to sixteen 
cells deep. In the xylem their walls are pitted ; in the phloem the walls are slightly 
thickened but bear no pits, and merge gradually into the pericyclar parenchyma. 
In a one-year-old stem the sieve-tubes are scarcely distinguishable, either in the 
phloem of the central cylinder or in the peripheral bundles, though they are readily 
seen in both tissues of a second-year stem. In all cases, the fusiform companion cells 
are prominent. De Bary (13) says, in describing the phloem of the peripheral bundles : 
“ It only consists of soft bast and in the main, at least, of parenchymatous elements ; 
sieve-tubes still remain to be sought for.” Herail (8) makes no mention of sieve- 
tubes in the peripheral bundles, though Lloyd W. Williams (14) states that, in 
comparing the bast of the peripheral bundle with the bast of the normal vascular 
ring, both contain sieve-tubes and companion cells, but the sieve-tubes in the former 
are far more numerous than in the latter. I found sieve-tubes in both tissues, and 
I agree with Lloyd Williams as to the great difference in the number of sieve-tubes, 
and I would further draw attention to the difference in the size of the sieve-plates 
themselves. 
Oleiferous cells occur frequently in the parenchymatous cortex but not elsewhere, 
though Lignier states that they occur in the pith and bast, and even in the cork 
underneath the old epidermis. He also states that the walls of the oleiferous cells 
are both lignified and suberised. Only in a few cases could I find traces of lignin. 
The periderm is formed in the secondary stem by the activity of an exodermal 
cambium. The walls of the cork cells outside the phellogen show marked foldings. 
Tannin deposits are found in the dried epidermis, and Lignier also finds resin. The 
cambial layer in the central cylinder is not so clearly marked as in C. floridus , and 
the same is true of the cambium of the peripheral bundles. The pith is hetero- 
geneous, and its small lignified peripheral cells contain large starch grains. The 
vascular tissue, both of the central cylinder and the peripheral bundles, contains 
abundant radiating needles of calcium oxalate. Lignier finds them also in the 
