SHOWING STRUCTURE, FROM THE RHYNIE CHERT BED, ABERDEENSHIRE. 863 
Fungus No. 14. (Figs. 48—56.) 
Fine mycelium with vesicles and resting-spores is not only met with in cells 
of the parenchyma of the vascular plants, but even more commonly invading, and 
developing within, the resting-spores of other fungal types. An example of this 
in the case of a fungus that also occurs distributed through the decaying tissues has 
already been seen in the case of Fungus No. 9, represented in fig. 36. A very 
definite and recurring example of this mode of occurrence in the large resting-spores 
of Fungus No. 3 is now to be described. Under the following type (No. 15) similar 
intrusive fungi within the smaller resting-spores of Fungus No. 2 will be described. 
The figured specimens will further afford additional examples of the resting-spores 
of Fungi Nos. 2 and 3. 
Fungus No. 14 was repeatedly met with in the peat of the lowest bed (A"l), 
especially in relation to Rhynia Gwynne-Vaughani, and recurred among Hornea 
in the upper part of the chert-bed (Bed N 20). 
Specimens such as that shown in fig. 48, which were first noticed, appeared like 
a distinct fungus of definite and peculiar shape. This had the form of a shortly 
stalked, spherical body about ’5 mm. in diameter. The stalk was evidently formed 
of numerous fine hyphse associated together. Similar fine hyphse formed a 
peripheral layer of the spherical body and extended among the thin-walled spores 
composing the central mass of this. The spores were spherical or oval, and could 
sometimes be seen to be borne on the fine hyphae. Some of the spores are shown 
more highly magnified in fig. 49. 
The explanation of the definite shape of this mass of fine hyphse bearing thin- 
walled spores was afforded by specimens such as those shown in figs. 50 and 51. In 
the specimen in fig. 50 the group of thin- walled spores is seen to occupy the cavity 
of a large resting-spore with the characteristic thick wall of Fungus No. 3. In this 
case the intrusive fungus completely filled the cavity of the large resting-spore. 
The spores of the intrusive fungus were less numerous and more loosely arranged 
in the otherwise corresponding specimen in figs. 55 and 56. 
The appearance of the stalk-like portion seen in fig. 48 is explained by the 
specimen shown in fig. 51. In this the outline of the partially decayed thick wall 
of the large resting-spore and of the stout hypha which bore it can be traced. The 
cavity both of the hypha and the spherical spore is filled by a fine mycelium, the 
spores on which are as yet undeveloped. In the light of this specimen it is easy 
to understand how the specimen in fig. 48 originated by the complete decay and 
disappearance of the hypha and the wall of the resting-spore that originally 
determined the shape of the intrusive mass of fungus. 
In other cases vesicles or spores of a similar fungus were developed on the 
outside of the large resting-spore. A specimen of this nature cut through the 
middle is shown from the cut surface in fig. 53. The thick wall and the contracted 
TRANS. ROY. SOC. EDIN., VOL. HI, PART IV (NO. 33). 133 
