370 SCIENCE PROGRESS 



y. The paving-blocks, used in the pavements referred to, 

 were dipped in creosote before use. Had they been fully im- 

 pregnated with that substance, the ravages of Lentinus lepideus 

 or any other wood-destroying fungus would have been pre- 

 vented. 



Much still remains to be done in elucidating the relationship 

 of wood-destroying fungi to living trees. Some years ago 

 Marshall Ward called attention to the fact that we knew prac- 

 tically nothing about Polypoms squamosus, one of the commonest 

 Polyporei in England. The writer undertook to investigate its 

 life-history, and in 1906 published a fully illustrated paper on 

 " The Biology of Polypoms squamosus, Huds., a Timber- 

 destroying Fungus." a A short account of the plant will now 

 be given. 



Polypoms squamosus, the Great Scaly Polyporus or Saddle- 

 back Fungus, is one of the best known of the tree-destroying 

 fungi. Its large ochraceous fruit-bodies, checkered with brown 

 scales above, are frequently to be seen projecting as conspicuous 

 brackets, either singly or in groups, from branches or the 

 trunks of trees in woods, parks, and gardens. The fungus 

 destroys a large number of ornamental trees, and has therefore 

 excited the interest of many who have the care of them. It is 

 not only common in Europe, but is also found in the United 

 States. Whilst residing in Munich the writer had frequent 

 opportunity of observing the fruit-bodies. In 1901 a series of 

 fine old Horse Chestnuts and Sycamores were cut down in the 

 Hof-garten owing to the majority having suffered from fungus 

 attacks. In three cases fruit-bodies indicated the presence of 

 Polypoms squamosus. During July 1901 four of the Red 

 Chestnut trees in front of the Wittelbacher Palast were bearing 

 fruit-bodies simultaneously. In the Englischer Garten two 

 Wych Elms and an Ash were found in a similar condition. In 

 England the fungus is equally common. Upon old trees in the 

 suburbs of Birmingham it was seen on the Beech, Sycamore, 

 Wych Elm, and Pirus vestita. The fungus was also noticed at 

 Sutton Coldfield, Havant, Banbury, Oxford, and on the Elms 

 in the Backs at Cambridge. Polypoms squamosus has never yet 

 been found on Pine, Larch, or other Coniferae. Otherwise it is 

 not particular in its choice of hosts, for various authors record 

 it upon the following trees : Sycamore, various species of Maple, 



1 A. H. R. Buller, Journ, of Economic Botany, 1906, vol. i. pp. 101-138. 



