SHOWING STRUCTURE, FROM THE RHYNIE CHERT BED, ABERDEENSHIRE. 897 
The abundance of fungi and the presence of an alga suggesting comparison with 
Characese are consistent with this. No evidence of marine conditions has been 
met with in the study of the plant-remains. The plant-containing chert discovered 
at Rhynie thus provides a special, but quite definite, record of a land surface covered 
with vegetation in the Early Old Red Sandstone of Scotland. 
EXPLANATION OF PLATES. 
(All the figures are from untouched photographs.) 
Plate I. 
Fungus No. 1. 
Fig. 1. A strand of stout septate hyphse from a longitudinal section of a partially decayed stem of 
Asteroxylon. x 100. (No. 2521.) 
Fig. 2. Strand of hyphse from the same stem with only very occasional septa ; at places the branched 
hyphse form irregular knots, x 100. (No. 2521.) 
Fig. 3. Septate hyphse from the strand in fig. 1. x 250. (No. 2521.) 
Fig. 4. Non-septate hyphse from the strand in fig. 2. x 250. (No. 2521.) 
Fungus No. 2. ( Palxomyces Gordoni.) 
Fig. 5. Portion of a longitudinal section of a stem of Asteroxylon. The soft tissues (phloem) of the 
stele are replaced by strands of stout, longitudinally running hyphse similar to those in the preceding 
figures. In the adjacent cortex are three large resting-spores of Fungus No. 2. x 34. (No. 2494.) 
Fig. 6. Portion of a longitudinal tangential section of a partially decayed stem of Asteroxylon showing 
hyphse and resting-spores of Fungus No. 2 in the middle cortex. x 50. (No. 2522.) 
Fig. 7. Portion of same section as fig. 6. x 100. (No. 2522.) 
Fig. 8. Some of the finer hyphse and collapsed vesicles in the same section. x 250. (No. 2522.) 
Fig. 9. Single resting-spore of Fungus No. 2 borne on a stout lateral branch of a more slender hypha. 
x 250. (No. 2522.) 
Fig. 10. Mature resting-spore of Fungus No. 2 showing the double contour due to the inner layer of the 
wall having separated from the outer layer, x 250. (No. 2522.) 
Fig. 11. Another resting-spore showing fine threads of wall substance between the outer and inner layers 
of the wall. x 210. (No. 2522.) 
Plate II. 
Fungus No. 3. ( Palxomyces Gordoni var. major.) 
Fig. 12. Large thick-walled resting-spores of Fungus No. 3 with, to the right, a resting-spore inter- 
mediate in size between this and the spores of Fungus No. 2. x 100. (No. 2527.) <, 
Fig. 13. Another specimen showing the stout hyphal stalk on which the resting-spore is borne, x 100. 
(No 2479.) 
Fig. 14. Portion of the wall of the resting-spore of Fungus No. 3 showing an outer layer, a broad 
middle layer, and an inner layer ; within the latter a thin layer bounding the contents is contracted away, 
x 250. (No. 2527.) 
