770 
Schwartz. — Observations on 
and stems were fixed in Bonin’s picro-formol solution. The plants were 
growing in dense shade, being overshadowed by taller herbaceous plants in 
the immediate vicinity. The soil was a loam in which clay predominated. 
In spite of the dry summer it had remained somewhat damp ; it was not 
particularly rich in humus. 
Microtome sections of the rhizome and root were cut, and were stained, 
some with Erlich’s haematoxylin and orange G, others with Benda’s iron- 
haematoxylin and orange G, and a few with anilin safranin. 
Structure of the Rhizome. A transverse section of the rhizome 
showed the usual dicotyledonous structure. The ring of vascular bundles 
was of typical appearance, and both fascicular and interfascicular cambium 
were well differentiated ; the hard bast was lacking. The cortical and pith 
cells were many of them filled with starch grains, although a few of the 
cells contained oil, presumably the f asarol 
No fungus was to be seen in any of the cells, nor were calcium oxalate 
crystals present either in the cells of the rhizome or of the leaf. 
Structure of the Root and its Mycorhiza. In transverse 
section the root showed either a diarch or triarch stele ; one such section 
with a diarch stele is shown in PI. LXXII, Fig. i. The endodermis had 
thickened walls, and showed the usual £ radial dot ’ on the side walls of its 
cells. The cortical cells of the root contained a lot of reserve starch, which, 
however, was lacking from the first two or three outer layers, and also from 
the innermost layers which formed the home of the ‘ mycorhizal 5 fungus. 
In roots free from the fungus, however, all the cells of the cortex contained 
starch grains except the few outer layers. 
Although the cortex of roots containing the mycorhizal fungus may be 
said to consist of three differentiated portions outside the endodermis — viz. 
(i) the outer cell layers, two or three in number, free from starch ; (2) the 
median three or four layers of starch-containing cells ; and (3) the innermost 
two or three layers with the mycorhiza and containing but little starch — 
these portions are, however, not sufficiently well differentiated and separated 
to admit of division into exocortex, mediocortex, and endocortex. 
In Thismia Aseroe these divisions are well differentiated, and Groom 
observed in the exocortex a number of sacs containing crystals of calcium 
oxalate in the form of raphides. Neither these nor any other form of 
calcium oxalate is to be seen in Asarnm. Outside the endodermis the 
first two or three layers of cells are occupied by the mycorhizal fungus, the 
cells of the layer abutting on the endodermis containing irregular-shaped 
masses of fungoid matter as shown in Figs. 1, 3 , and 3. These masses are 
highly refractive and are composed of dead portions of fungus, only slender 
portions of hyphae being as a rule distinguishable in them. The cells are 
mostly devoid of starch, and are of normal shape and appearance ; their 
nuclei, when visible, show no signs either of hypertrophy or degeneration. 
