KNOWLEDGE OF MONOCOTYLEDONOUS SAPROPHYTES. 193 
narrower than those composing the greater part of the ground- 
tissue, but stil very broad, considering their location. There 
are a few sieve-tubes with very distinct calli on the sieve-plates, 
aud narrow companion cells. The xylem is not less remarkable ; 
it is made up of large reticulo-spiral tracheides (or trachez ?) with 
relatively thin walls, many of them being of extraordinarily 
wide calibre (Pl. VI. fig. 3). 
The small leaf-trace bundles in the cortex are composed of 
narrow tracheides, sieve-tubes, and parenchyma. The sieve- 
tubes extend nearer to the scale-bases than do the tracheides. 
The cells comprising the cortical parenchyma just at the point 
of insertion of the scale, and mesophyll of the scale itself, have 
markedly pitted walls. 
No traces of mycorhizal hyphe occurred within the axis itself, 
though the inner epidermis of the scales had conspicuous mycelia. 
Mycelial masses were absent from scales and axis. 
Histology of the Inflorescence-axis. 
The axis is hollow at the internodes. The epidermis consists 
of exceedingly elongated narrow cells. No stomata or hairs 
occur, excepting that at the base of the axis a few hairs are 
found where the axis commences to be visible between the scale- 
leaves. The walls are very thin and feebly cuticularized. In 
the internodes a number (about 25) of layers of parenchymatous 
cells with delicate walls lie within the epidermis, and amongst 
them are relatively well-developed intercellular spaces. Towards 
the periphery some of these contain mucilage and raphides. 
Only those cells immediately round the vascular bundles possess 
starch, and then in a small quantity. There is no trace of a 
general sclerenchyma-sheath. The vascular bundles are disposed 
in several circles, but the outer layers of the ground-tissue are 
devoid of bundles. The phloém is well developed, its paren- 
chymatous cells being much narrower than in the rhizome. All 
the constituents of the phloém are more protoplasmic and 
have richer contents than in the rhizome. In comparison with 
the rhizome, the difference in the zylem is most marked. The 
conducting elements are much reduced in calibre, being repre- 
sented by a number of very narrow annular and spiral vessels. 
No pitted tracheides occur here or in the rhizome. In each 
of the inner bundles a lysigenous intercellular space is formed 
