KNOWLEDGE OF MONOCOTYLEDONOUS SAPROPHYTES. 163 
the base of the roots of B the starch is collected in the endocortex 
rather than in the mediocortex, which has but little in its outer 
layer. And corresponding to this increased amount of starch in 
the endocortex, the raphide-mucilage sacs are more abundant in 
the endocortex than in the mediocortex. 
Origin of the Roots. 
In Galeola the roots are unbranched ; new roots arise at the 
flowering axes. I cannot certainly state how the root arises; 
but, from the single very young one which I saw, it seems pretty 
certain that the roots arise in the inflorescence-axis, not from 
the pericycle, but by differentiation in the immature cortex; the 
epidermis of the axis does not appear to aid in forming the root. 
If this be correct, the mode of origin is strikingly like that in 
Neottia. 
Summary of Results concerning the Root. 
1. The piliferous layer produces but few short hairs. In most 
places it peels off. There is no definite regular exodermis, but 
everywhere, beneath the piliferous layer or exposed to the surface, 
the root-cortex is coated by cells with at least the external walls 
thick and suberized, even at the growing point. These cells are 
admirably calculated to prevent loss of water, but it appears that 
absorption of solutions can only take place at spots perforated 
by the mycorhizal hyphe. 
2. Beneath succeed about 3 layers (3-5) of thin-walled cells, 
constituting exocortex with active mycelia in most of the cells. 
Starch is present only in cells devoid of mycelia. The hyphe 
can be traced to the outside of the root. 
3. So far as can be judged by the structure of the superficial 
layer and exocortex, the older parts of the roots are just as 
capable of absorbing solutions as are the young parts. 
4. Within, succeed layers of cortex capable of being occupied 
by mycelial masses (mediocortex), and rich in starch and in 
raphide-mucilage sacs. 
5. These layers are succeeded by the endocorter, which is 
incapable of entertaining the mycelia and is poorer in starch. 
6. The endodermis has thin suberized walls. When a single 
layer of mechanical cells lies outside it, this layer has passage- 
cells outside the passage-cells of the endodermis, z. e. opposite 
the bundles of xylem. 
