KNOWLEDGE OF MONOCOTYLEDONOUS SAPROPHYTES. 187 
I had only one uninjured root-tip at my disposal. All that I 
can safely say with reference to it is that a root-cap was 
present. 
Several roots showed processes of decay commencing at their 
apices. Fungal hyphe made their way most rapidly up the 
stelar tissue; they traversed the cortex more slowly, as the 
cortical cells temporarily parried the attack by a thickening of 
their walls at the point of contact with the hyphe. 
Histology of the Shoot. 
(.) Inflorescence-azis. 
(A) Basal region immediately above the attachment of the 
roots. 
The axis is externally clothed by an 
(1) Epidermis composed of longitudinally extended narrow 
cells. The walls have a tolerably thick cuticle, and the lateral and 
inner walls are suberized. The walls are in addition coloured 
blackish-brown, possibly owing to attacks by fungi.  Stomata 
are present, and there appear to be traces of decayed hairs. 
(2) Within succeed some layers of parenchyma with thin walls, 
elongated longitudinally, and polygonal in transverse section. 
Raphide-mucilage cells occur isolated amongst these. (3) There is 
a general sclerenchymatous sheath, composed of about five layers 
of fibres. Towards the interior, these gradually pass into (4) the 
conjunctive parenchyma of the stele, the cells of which have thick, 
pitted, lignified walls. In comparison with the general sheath 
the conjunctive tissue is made up of shorter cells with wider 
lumina, and the intercellular spaces between them are better 
developed. (5) The scattered vascular bundles are larger than in 
the root. The vascular bundles lying near the general sheath 
are more or less collateral, but in transverse section are often 
peripherally elongated rather than radially extended. Towards 
the centre the bundles are not collateral, but display curious 
arrangements, which may be roughly described as transitions 
from a radial to a collateral arrangement, the xylem and phloém 
being more or less intermingled. Pl. V. fig. 7 shows a bundle 
which is almost collateral, but the protoxylem does not lie 
exactly on the same radius as the phloém. The pAloém, in 
comparison with that in the root, is relatively more increased 
than is the xylem. It consists of considerable masses of elongated 
