PENICILLIUM AS A WOOD-DESTROYING FUNGUS. 
By H. MARSHALL WARD, D.Sc., F.R.S., Professor of Botany in the University of 
Cambridge.* 
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Spores from pure cultures of fenici/lium were sown on sterilised 
blocks of spruce-wood, cut in March, and were found to grow freely 
and develop large crops of spores on normal conidiophores. Sections 
of the infected wood showed that the hyphz of the mould entered 
the starch-bearing cells of the medullary rays of the sap-wood and 
consumed the whole of the starch. The resin was untouched. In 
culture three months old the hyphe were to be seen deep in the 
substance of the wood passing from tracheid to tracheid vid the 
bordered pits. Control sections, not infected and kept side by side 
with the above, contained abundance of starch, and no trace of hyphe 
could be detected in them. 
The observation appears of interest in several connections. Penicillium 
is one of our commonest moulds, and undoubtedly plays a part in the 
reduction of plant débris to soil-constituents ; how far it can itself 
initiate the destruction of true wood, or how far it merely follows on 
the ravages of other fungi, bacteria, &., is unknown. There. are 
strong grounds for believing that it destroys the oak of casks, &c., but 
since these are impregnated with food-materials, this is not very 
surprising. Trabut? has shown that penicillium will grow in solutions 
containing 2-9°5 per cent. of CuSO,, and other evidence exists show- 
ing how remarkably resistant this mould is, and how little organic 
matter it needs for life. : 
; Dubois? showed that penicillium, or a closely-allied form, not only 
lives in strong solutions of copper, neutralised with ammonia, but will 
erode metallic copper and bronze if transplanted thereon. 
I6nssen3 found penicillium living in one-tenth normal sulphuric acid 
solution, and gives some interesting facts regarding the sulphur- 
containing oil-drops in its protoplasm, and other statements concern- 
Ing oil in this fungus occur in the works of De Bary, Brefeld, 
Pfeffer, &c. 

