E. &. BUTLER: 17 
surface becoines strongly convex, the lower less or almost. flat. 
Soon the colour deepens into a characteristic chestnut shade on 
the top, while the upper surface becomes clothed with thick soft 
hairs formed of agglutinated threads. At the same time hundreds 
of small pores are formed on the under surface, and these develop 
into long yellowish brown tubes, which often exude water in drops 
while forming, even in dry weather. The body remains soft until 
quite old when it becomes hard, black, shrunken and _ cracked. 
The inner flesh always retains a deep yellowish or almost chestnut 
brown. 
Within the tube, spores are formed in large numbers on special 
cells which Jine their walls. Each such cell bears four spores on 
short stalks. The spores are smooth, single-celled, egg-shaped 
and brown. They are shed through the tubes into the air. 
Infection only takes place by means of spores blown from the 
spore-bodies on the surface of diseased trees. 
The remedy consists in cutting out the affected part, when 
this is a branch, and can be recognised by the presence of the 
spore-bearing bodies ; in taking care to remove and destroy the 
latter as soon as they are noticed on the surface ; above all, in 
endeavouring to reduce chances of infection by removing the 
branches during pruning or when feeding the worms, in such a 
manner as to promote rapid healing of the scars. It is noticeable 
that the fungus is much commoner on mulberries than on apples 
or plums, and this is undoubtedly due to the abundance of unhealed 
wounds on the former. 
It is probable that the regulation prohibiting the felling of 
mulberry trees in the Valley is too strictly enforced. ‘There are 
many old trees hollowed by the action of trunk-rot, which would 
be better out of the way. They yield leaf of poor quality and 
bear annual crops of Polyporus hispidus which must lead to the 
infection of neighbouring trees. It would be a comparatively 
simple matter for the mulberry inspectors to mark such trees, 
whose removal could then be permitted on condition that they 
are replaced by a certain number of seedlings. 
