On Polyporus squamosus Hints. c>71 
In the case of the Horse Chestnut wood, sterilisation was 
1 
effected by treatment with hydrogen peroxide, the excess being 
subsequently removed by treatment with dilute potassium per¬ 
manganate solution acidified with sulphuric acid. The blocks so 
treated remained sterile, and no discolouration of the wood took 
place, while in most cases the mycelium grew fairly readily on those 
inoculated. 
(b). The development of abnormal fructifications. The first sign 
of any fructifying bodies appeared on one of the original Elm wood 
cultures towards the end of April, 1912, about eight months after 
it was set up. Later many of the other cultures growing in dull 
light also produced fructifications of a similar type, chiefly in June 
and July. Thus on August 7, 1912, there were thirteen fructi¬ 
fications, some produced from blocks inoculated on October 23, 
1911, and others from blocks inoculated as late as March 5, 1912. 
Each fructification arose as a small white or brownish hemi¬ 
spherical excrescence from the general mycelium, often from near 
the upper end of the block of wood, but in one case from the surface 
of the cotton wool plug, near the wood, which the mycelium had 
permeated. Growth proceeded rapidly, but the fructifications 
produced never took the normal bracket form. 
Often they appeared as unbranched structures, of an “ Indian 
club” shape, though only slightly enlarged at the distal end (see 
PI. VI, Fig. 2), but some were variously branched, producing 
peculiar “ tree like ” growths such as those shown in PI. VI, Fig. 1. 
They show a geotropic response, as they assume a more or less 
vertical direction of growth after first growing out at any angle. 
As they get older they become dark brown in colour, often only 
just the tip of the fructification appearing white. These fructi¬ 
fications remained quite sterile, microtome sections cut in various 
regions failing to show any sign of the formation of a hymenial 
surface or of basidia. 
In general appearance the fructifications are on the whole 
similar to those described by Buller (7, pp. 57-59) as developed in 
the dark, on logs which were badly attacked by the mycelium. 
That the cultures here described failed to develop piiei in the 
light, must be attributed to conditions of culture, such as the very 
restricted air supply which is present in the tubes, and the 
comparatively small amount of food material present. Lakon (8) 
and Miss Bayliss (1, p. 8) have shown that there is undoubtedly 
an inhibitory effect on development connected with such a restricted 
air supply. 
