FORESTS 



FORESTS 



347 





'.i- 



\ 



facilitate the healing process. In large forest 

 tracts measures of this kind may not yet be prac- 

 ticable, and in such cases the only preventive 

 measure is to destroy the source of infection, as 



far as pos- 

 sible. On 

 limited 

 areas it is 

 possible to 

 remove the 

 punks or 

 fruiting 

 bodies of 

 the w d- 

 destroying 

 fungi and, 

 better still, 

 to cut down 

 all trees 

 which show 

 any signs of being dis- 

 A careful weed- 

 ing out of diseased trees 

 will remove the source 

 of infection for the 

 other trees, to a very 

 large extent. 



In hewn timber. — The 

 decay of cut wood may 

 be retarded or pre- 

 vented by various 

 means. The easiest way 

 to prevent the develop- 

 ment of the fungi is to 

 " treat " all wood which 

 is exposed to atmos- 

 pheric agencies. Charring will frequently be found 

 useful. For getting longer service out of wood, it 

 should be chemically treated by painting.with some 

 preservative, such as carbolineum or coal-tar creo- 

 sote. Care should be taken, however, that only 

 absolutely dry wood is painted. Timber immersed 

 in a solution of one part of corrosive sublimate to 

 150 parts of water will be proof against the attack 

 of decay-producing fungi for many years. The best 



Fig. 495. Tinder fungus (Poly- 

 porus igniarius) on beech 

 log. The external part of 

 the fungus is shown be- 

 low; the h6art-);ot injury 

 above. 



Fig. 496. Red heart disease of Douglas spruce {Trametes pini) . 



preservative is undoubtedly coal-tar creosote, which 

 can either be 'painted on the wood or be pressed 

 into it by various mechanical devices. 



Literature. 



The following are some of the more important 

 books and papers relating to the diseases of 

 American trees and timber : G. F. Atkinson, Studies 

 of Some Shade Tree and Timber Destroying Fungi, 

 Cornell Agricultural Experiment Station, Bulletin 

 No. 193 (1901); E. M. Freeman, Minnesota Plant 

 Diseases, Chapters on Diseases of Timber Trees 

 (1905); Galloway and Woods, Diseases of Shade 

 and Ornamental Trees, United States Department 

 of Agriculture, Yearbook 1896, p. 237; Robert 

 Hartig, Diseases of Trees (1894); F. D. Heald, A 

 Disease of Cottonwood, Nebraska Agricultural Ex- 

 periment Station, Bul- 

 letin No. 19 (1906); 

 Perley Spaulding, A 

 Disease of Black Oaks, 

 Report Missouri Bo- 

 tanical Garden (1905) ; 

 the following by Her- 

 mann von Schrenk: A 

 Disease of Taxodium, 

 and of Libocedrus, Re- 

 port Missouri Botan- 

 ical Garden, No. 11 

 (1899); A Dis- 

 ease of the 

 Black Locust, 

 Report Mis- 

 souri Botan- 

 ical Garden, 

 No. 12 (1901);' 

 The Bluing and Red 

 Rot of the Western 

 Yellow Pine, Bu- 

 reau of Plant In- 

 dustry, Bulletin 

 No. 36 (1903); Dis- 

 eases of New Eng- 

 land Coniferous 

 Trees, Division of 

 Vegetable Physiol- 

 ogy and Pathology, 

 United States De- 

 partment of Agriculture, Bulletin No. 25; Fungous 

 Diseases of Forest Trees, United States Department 

 of Agriculture, Yearbook, 1900; Two Diseases of 

 Red Cedar, Division of Vegetable Physiology and 

 Pathology, United States Department of Agricul- 

 ture, Bulletin No. 21; A Disease of White Ash, 

 Bureau of Plant Industry, Bulletin No. 32 (1903); 

 Decay of Timber, Bureau of Plant Industry, Bulle- 

 tin No. 14; Diseases of the Hardy Catalpa, Bureau 

 of Forestry, Bulletin No. 37; Diseases of the 

 Redwood, Bureau of Forestry, Bulletin No. 38; 

 Seasoning of Timber, Bureau of Forestry, Bul- 

 letin No. 41; C. S. Sargent, Silva of North 

 America (has numerous notes on fungous and 

 insect diseases of trees); C. Freiherr von Tubeuf, 

 Diseases of Plants, Longmans, Green & Co., New 

 York (1897). 



Fig. 497. Mistletoe forming "bird's 

 nest" on lodge-pole pine. 



