824, REPORT—1904. 
A number of rotting blocks, obtained from time to time from the streets, were 
placed in a large damp-chamber. In the course of a few weeks fruit-bodies of 
Lentinus lepideus appeared upon them. 
The spores remain unchanged in distilled water and tap-water, but germinate 
readily in Pasteur’s Fluid and in beef-gelatine. They also germinate in decoctions 
of horse-dung and of pine-wood. 
The pavement is probably infected by spores after the blocks have been laid 
down. ‘The mycelium of the fungus often grows from a rotten block to the 
neighbouring sound ones. No fruit-bodies are produced in the streets, owing to 
the traffic. 
The wood is rotted by Lentinus /epideus in very much the same manner as by 
the Dry Rot Fungus (Merudius lacrimans), It becomes red and is spongy when wet. 
It shrinks and cracks considerably on drying, and is then very brittle. Cellulose 
is removed from the cell-walls. Hadromal and a red friable substance are left - 
behind. 
The paving blocs, used in the pavements referred to, were dipped in creosote 
before use. Had they been fully impregnated with that substance, the ravages of 
Lentinus lepideus or any other wood-destroying fungus would have been prevented. 
18. The Reactions of the Frivit-bodies of Lentinus lepideus, /r., to 
External Stimuli. By A. WW. Reetwwatp Buiter, D.Se., Ph.D. 
The fruit-bodies of Lentinus lepideus were grown upon rotting paving blocks, 
taken from the streets of Birmingham. The fungus belongs to the Agaricini. 
The papille, from which the fruit-bodies arise, are not somatotropic, so far as 
the surface of the wooden substratum is concerned, but grow out perpendicularly 
to the surface of the mycelial layer on which they develop. Their formation takes 
place equally well in light or darkness. 
Before the development of the pileus, the stipe is perfectly indifferent to 
geotropic stimuli. In the absence of light it is rectipetal, and in its presence 
positively heliotropic. 
In the absence of light the stipe may continue to grow for weeks or 
months, and may attain a length of 17 centimetres, but no signs of a pileus make 
their appearance. The development of the pileus depends on the presence of 
sufficient illumination. Grown in the dark, therefore, the fruit-bodies are all 
monstrous and abortive. 
While the pileus is developing, the stipe alters its reactions to external stimuli. 
It becomes negatively geotropic and ceases to be heliotropic. 
The pileus is sometimes developed unequally in fruit-bodies with oblique stipes. 
The longest gills are always formed on the lower side of the stipe. The inequality 
of development is induced by the stimulus of gravity. 
The gills begin their development in such manner as to become perpendicular 
to the surface of the pileus, from which they are formed. They are never helio- 
tropic, but they become positively geotropic. 
Fruit-bodies grown in darkness or weak light are prone to branching, and 
often become grotesque. Branching may be due to internal causes or to injury of 
young pilei. 
It may be shown that the reactions of the fruit-bodies to external stimuli, as 
described above, are admirably adapted for the economical distribution of the 
spores. 
19. The Structure of the Ascocarp in the Genus Monascus. 
By B. T. P. Barker, J/.A. 
Since the publication of the author's earlier paper on this subject Ikeno and 
Dangeard have published accounts of the structure of the ascocarp of Monascus 
purpureus, and the latter also describes the ‘ Samsu’ fungus, which he has named 
