T nK I'AKASITK' FI'Ni.I "N THE ( 'ELL- \VAl.I.. .'57 



accompaniment of the attacks of wood-destroying fungi mi tin- 

 woody parts of trees and shrubs. P>e>ides actual perforation 

 of the lignified membranes of their host, the hyphae of many. 

 of the Polyporeae ami Agaricini exert a solvent effect <m the 

 walls, which extends over a considerable area, and is evidently 

 due to the excretion of some ferment. The dissolution of the 

 walls takes place, moreover, in a way so characteristic for each 

 species of fungus that they can be determined by it alone. From 

 this it must be deduced that each wood-destroying fungus 

 excretes a ferment peculiar to itself, which causes a character- 

 istic dissolution of the host. Our present sources of infrma-. 

 tion on these points are the very valuable investigations of 

 1'iofessor Robert Hartig of Munich. 1 Some of his results will 

 repay <ur careful consideration, but we must preface briefly 

 some tacts regarding the process of lignification ami the forma- 

 tion of heart-wood in our forest-trees. 



The elements of the wood of dicotyledonous trees and woody 

 plants are derived from the cambium; their walls consist at 

 tir-t of pure cellulose, and when lignitication takes plac t!:e 

 .-"-called incru-ting substances are laid down in the thickened 

 cellulo-e wall, particularly coniferin, vanillin, wood-gum, tannin, 



. : or as they may be coll.-ctively called, lignin. The cellulose 

 memlirane itself is coloured lilac with clilor-xinc-iodine : when 

 lignilied it no longei 1 shows this reaction, but has others p'-culiar 

 to itself, the best known being red coloration on treatment 

 with phloroglucin and hydrochloric acid, or yellow coloration 

 with aniline sulphate; ehloi-xinc-iodine colours lignified ti>Mies 

 brownish-yellow. ( lopper-ammonram-hydrate dissolves celb;'. 

 but not wood.- If the incrusting substances be removed from 

 the liijnitied meinbraiies liy treatment with Schulxe's solution, 

 caustic >oda, or other solvent, the cellulose remains and reacts 



-uch. In the process ,,f (-.inversion of alburnum into dura- 



1 Tin- m<i.-t important <>f tlir~r work- are: 



ha ZersetzungsfTscheinungen <l. //'</.<></. Nadelh&lzer n. >l. /.'/<//. \\itli i'l 

 <<.!(, uri-il jil/iti--. S|n iiiji-r. Berlin, 1^7^. 



I >' r ''//>' ffau&tckioamm, .\f> i-n/in-t /</-/, i-i/mmi*, Iss.'i. 



\\'i'-li'i'i' K i'< iil:h> /'.'< // i/. l\'n/i/li<itun. . Is74. 



/, tii-i'iK-li /. Baumkrankheiten, I. ami 11. l-Mnlon, |s->-j .unl ISM 



ti.in-l.it ion ot II. I-]. lit. l,y I'fof. \\'. Suiin-rvilli'. 



Lelirbuch if. .ln<it"ni" u. /'/{//-n:/,,./;. ./. / l^'.M. 



-' l''oi furt In-! Hit We : 



XiniiiiiTiiiiiiiii. />> Ixit'ini^-li- M t, ,<>> i-lunl.. Is'.l'J. 

 Li-Inn L'-r. />n- l-i./'iin ->! /'i'i/.-ti/:iiiii. Iss7. KiiL'li-li I'Mition, 



