37 6 SCIENCE PROGRESS 



four years. A number of interesting observations were made 

 upon the development of the fruit-body. Zoning of the upper 

 surface of the pileus seems chiefly due to an alternate checking 

 or promotion of growth caused by changes in the amount of 

 moisture in the atmosphere. Fruit-bodies of irregular shape, 

 but nevertheless producing spores, were developed on a stick 

 which was rotated on a klinostat for four months. It was 

 proved that light is necessary for the development of the 

 hymenium, but that the form and position of the fruit-bodies 

 are determined by geotropic stimuli. The dried spores were 

 found to retain their vitality for eleven weeks. 



The writer will shortly publish his researches 1 on the 

 production, liberation, and dispersal of the spores of Hymeno- 

 mycetes. The fruit-bodies of the wood-destroying fungi, 

 regarded as spore-producing organs, will be dealt with in 

 some detail. Among other points evidence will be brought 

 forward to show that the fruit-bodies of Polystictus, Stereum, 

 Lenzites, and other leathery or corky species found on wood 

 are xerophytic. On desiccation they retain their vitality for 

 months, or in some cases years. With access to moisture they 

 completely recover and shed vast numbers of spores. 



The question of preventing the decay of timber is one ol 

 great economic importance, and has long attracted attention in 

 this country. According to Boulton, 2 already " by the year 1838 

 four several systems of antiseptic treatment were fairly before 

 the public and competing for the favour of engineers. These 

 were corrosive sublimate, sulphate of copper, chloride of zinc, 

 and heavy oil of tar." Soon after their formation the railway 

 companies found themselves obliged to protect the sleepers from 

 decay, and hence they have been very active in making extended 

 experiments and observations on timber preservation. Long 

 experience has now proved beyond a doubt that there are 

 •certain salts and substances which, when injected into wood, 

 prevent its decay, and so greatly lengthen its period of use- 

 fulness. It is also certain that antiseptic treatment pays. The 

 chief question of importance at the present day is that of 

 deciding which of the various processes known can be used 

 to greatest advantage for railway sleepers, fence posts, bridge 



1 Researches on Hymenomycetcs, Longmans, Green & Co. 



2 S. B. Boulton, " On the Antiseptic Treatment of Timber," Minutes of Proceed- 

 ings of the Institution of Civil Engineers, vol. 78, 1884, p. i02 § 



