332 Groom. — On Thismia Aseroe ( Beccari ) 
of inflorescence-axes. The mode of growth is represented by 
Fig. i. The axis grows by means of an apical growing-point, 
and on it arise, in acropetal succession, similar lateral branches. 
But at the points of insertion of these secondary axes, other 
branches arise subsequently on the side towards the apex of 
the main axis : so the false appearance is produced of a 
number of tertiary axes in the axils of the secondary. Of 
these tertiary axes one at least is a bud of an inflorescence- 
axis. As a rule the tertiary absorbing organs grow more 
rapidly than the buds ; consequently distinct tufts of small 
absorbing organs are visible at regular intervals on the main 
axis. The main axis decays from behind, and it seems 
probable that its lateral absorbing organs thus become 
separate individuals. 
Taking sections through a mature but not too old portion 
of a vegetative axis, the following structure is revealed (Figs. 
2, 3. 4, 5 a, 5 
(i) Sheath. — There is no definite regular layer of cells cloth- 
ing the surface. Some of the external cells are elongated at 
right angles to the surface and form short hair-like outgrowths. 
But often a delusive appearance of hair-production is caused 
by the cells, which are elongated longitudinally, partially 
separating from the subjacent cells and the free portion 
protruding outwards. A very feeble cuticle coats the outer 
walls of the superficial cells. Within succeed about 3-3 layers 
of cells with small intercellular spaces. They are elongated 
longitudinally. These and the cells exposed to the surface 
agree in being parenchymatous cells with thin cellulose-walls, 
having a delicate protoplasmic lining and a large amount 
of cell-sap, but no starch ; in fact they might be described as 
constituting an aqueous tissue. They may be collectively 
referred to under the name of the sheath. Amongst the 
sheath-cells are raphide-mucilage cells. The most striking 
feature about this tissue is that straight fungal hyphae (my- 
corhizal) run through some of the cells. These hyphae 
traverse the centres of the cells running in a longitudinal 
direction with wonderful straightness. Here and there they 
