3 68 SCIENCE PROGRESS 



stituents by the enzyme which he has named hadromase. The 

 cellulose set free can then be broken down by cytase. The 

 chemistry of lignified cell-walls is still to a large extent a 

 matter of conjecture. Only when it becomes more full}* cleared 

 up can we expect to understand many of the chemical changes 

 taking place in rotting wood. 



In America, von Schrenk 1 has published a number of papers 

 upon the destruction of wood and the diseases of forest trees. 

 His work is of practical as well as of scientific interest. 



In 1905 the writer 2 gave an account of the destruction of 

 wooden paving-blocks by Lentinus lepideus, Fr. Fig. 1 shows 

 the relationship of the fungus hyphae to the wood-cells. 



The following is a summary of the conclusions arrived at : 



1. The destruction of a large number of paving-blocks, made 

 of pinewood, in the city of Birmingham, is being brought about 

 by Lentinus lepideus, a fungus belonging to the Agaricini. 

 Considerable repairs to the pavement are thereby necessitated. 



2. Single blocks or small groups of blocks at intervals in the 

 streets go completely rotten, so that one can break up the wood 

 with the fingers. The streets affected become unduly bumpy. 

 In wet weather puddles collect above places where rotten 

 blocks are. 



3. 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. 



4. 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 horsedung and 

 of pinewood. 



5. The pavement is probably infected by spores after the 



1 Hermann von Schrenk, U.S. Dep. of Agric, Veg. Phys. and Path., 1900 

 Bull. 25, " Some Diseases of New England Conifers " ; ibid., 1900, Bull. 21, "Two 

 Diseases of Red Cedar" ; Twelfth Ann. Rept. Missouri Bot. Gardens, 1902 ; 

 Journ. IVes/em Soc. Engineers, 1901 ; " Factors which cause the Decay of \Yood,' : 

 Contribution 19, Shaw School of Botany, St. Louis ; "Fungus Diseases of Forest 

 Trees," Yearbook, U.S. Dep. of Agric, 1900 ; U.S. Dep. of Agric, Plant Industry,. 

 Bull. 14, 1902, "The Decay of Timber and Methods of Preventing it"; ibid., 

 Bull. 32, 1903, "A Disease of the White Ash caused by Polyporus fraxinophilus" ; 

 ibid., Bull. 36, 1903, "The Bluing and Red Rot of the Western Yellow Pine, etc." 



2 A. H. R. Buller, "The Destruction of Paving-Blocks by the Fungus Lens- 

 tinus lepideus, Fr.," Journ. of Economic Biology, 1905, vol. i. 



