437 
Lentimis lepideus, Fr., to External Stimuli. 
Fig. 6. Nat. size. A number of papillae and conical protuberances arising on a mycelial layer 
covering the end of a piece of a rotten paving block. The development took place in moderate light. 
Figs. 7-9. Nat. size. All the same fruit-body and illustrating the positive geotropic reaction 
of the gills. 
Fig. 7. The fruit-body developed in the normal vertical position (as in Fig. 1). It was then 
turned through a right angle and placed on its side as in this figure. All light was then carefully 
excluded from it. 
Fig. 8. The same fruit-body after two days. The gills have grown towards the earth. They 
have become much longer, and their edges have developed the torn appearance characteristic for the 
genus Lentinus. The whole pileus has turned upwards slightly. 
Fig. 9. The fruit- body of Fig. 8 photographed from below. The gills were pointing vertically 
downwards. 
Fig. 10. Nat. size. Three young fruit-bodies grown in moderate light. The uppermost is 
aborted and has ceased its development. The lowest one, although still growing, shows no signs 
of a pileus. The middle one is producing a pileus symmetrically. Drops of water have been 
excreted upon it. The rudimentary gills are scarcely visible. The whole group is photographed 
from below. 
Fig. 11. Nat. size. The middle fruit-body of Fig. 10 at a later stage and photographed from 
the side. The pileus has become erect owing to the curvature of the end of the stipe. 
Fig. 12. Mag. The top of a paving block kept in complete darkness in a damp-chamber. 
From the mycelial layer two rods have grown out. That on the right has grown upwards at an 
angle of about 45 0 with the vertical. The other one has grown more or less parallel to the upper 
surface of the block. There are no signs of pilei. 
Fig. 13. Mag. f. Paving block kept in complete darkness. A white layer of mycelium 
formed upon the surface of the wood and gave rise to numerous papillae, a number of which have 
developed in the course of about five weeks into monstrous fruit-bodies showing no traces of pilei. 
Fig. 14. Nat. size. The stipe grew from the wood towards the light. A pileus is in a very 
early stage of formation. As yet there are no signs of gills. 
Fig. 15. Nat. size. A fruit-body with short stipe and broad decurrent gills. Drops have been 
excreted upon the gills, which have torn edges. 
Fig. 16. Nat. size. Another fruit-body with a long stipe. The pileus is chiefly developed on 
the side towards the observer. The gills are not yet fully grown, and have intact edges. 
Fig. 17. Mag. §. Monstrous fruit-bodies photographed from above after growing from the 
mycelial layer on the wood for six weeks. There are no signs of pilei. 
Fig. 18. Mag. -fa. Paving block, found among a pile of blocks which had been removed from 
a street in Birmingham. A monstrous fruit-body, branched like an elk’s horn and devoid of pileus, 
had grown upon it. 
Fig. 19. Mag. Another photograph of the block shown in Fig. 17, again taken from above. 
The longest rod had attained a length of nearly 7 inches during nine weeks’ growth. It had turned 
a rich rusty brown colour. Three young white protuberances are to be seen towards the centre of the 
block. They are growing out almost parallel to the surface of the wood. 
Fig. 20. Mag. The same block and monstrosities as in Fig. 13. The rods had been 
growing in darkness for about nine weeks. There are no signs of pilei. The lower part of the rods 
had turned brown. The rods had become depressed owing to their own weight. The damp- 
chamber, with glass walls, was situated in a dark room used for photography. The occasional light 
was sufficient to give a heliotropic stimulus to the rods. They all grew towards the source of light. 
DRAWINGS. 
Fig. 21. Nat. size. A diagram to illustrate direction of outgrowth of fruit-bodies, w, block 
of wood ; m, mycelial layer ; /, papillae growing out perpendicularly to the mycelial layer and 
incidentally perpendicularly to the surface of the wood ; o, o 1 , papillae growing outwards perpen- 
dicularly to the edge of the mycelial layer and incidentally obliquely to the surface of the wood. 
Fig. 22. Nat. size. To illustrate heliotropic curvature. The light was at first direct on to the 
block in the direction indicated by the arrow a. The rods 0, p, r, and s grew towards the light. 
The block was then moved round in a horizontal plane through two right angles, so that the light 
was directed as indicated by the arrows bb. The rods 0 and p gradually grew in a curve through 
