29 
and Helminthostachys zeylanica . 
making their way out to ramify in the soil, is clear from the 
relations of the hyphae at the points in question. Thus the 
entering filament is almost always given off at right angles 
from a hypha crossing the outside of a hair, and, when the 
first branching of the hypha within the prothallus is visible, 
it always suggests the subdivision of an entering hypha 
(Fig. 1 6). The penetrating hyphae, like those on the outside 
of the prothallus, are of considerable thickness. They are at 
first straight and run at right angles to the surface. Some- 
times the hypha branches while in the hair, but more often 
this does not take place until it has penetrated to the hypo- 
dermal layer. In this there is often a considerable horizontal 
extension of branches from which vertical hyphae in turn 
originate. In the cells below the hypodermal layer other 
structures begin to make their appearance, these are small 
thin-walled vesicles (Fig. 17), the connexion of which in 
bunches borne on fine hyphae can now and then be traced. 
A number of these vesicles occur in each cell, often close to 
the nucleus. They are filled with protoplasm, in which 
a number of small nuclei are distributed. Other cells contain 
thick coiled hyphae, while in the older regions thick-walled, 
irregularly-shaped bodies of a brown colour are occasionally 
found. The mode of development and the function of these 
latter bodies is uncertain. 
The general characters of the mycorhiza of the prothallus 
of Ophioglossum pendulum agree closely with those of the 
Fungus found by Janse 1 in the roots of the plant. The 
starch-containing vesicles, mentioned by him, have however 
not been seen. Numerous plastids occur in the cells of 
the prothallus, and these, both towards the apex of the 
branch and in cells occupied by the Fungus, contain abundant 
starch. 
The antheridium originates from a single superficial cell, 
the first division in which is parallel to the surface. The 
outer of the two cells thus separated gives rise to the one- 
layered wall : the inner undergoes numerous divisions and 
1 Ann, Jard. Bot. Buitenzorg, xiv, PI. IX, Figs. 11-13. 
