POLYPORUS. 117 



in greater detail the destruction brought about by it- mycelium. 

 He found that it penetrates lignitied cell- walls, entering the livim: 

 elements and causing their death: it spreads most laj.idly in the 

 vertical direction through wood, hast. and rind, growing through 

 parenchyma and sieve-tubes. and even boring its way into tin- 

 sclerenchymatous stone-cells; it absorbs the secondary thickenm- 

 by dissolving out first the ligneous incrustation, next the cellul 

 while the middle primary lamella remains liehind untouched. 



Polyporus (Fomes> fulvus (Scop.) ( I'.ritain i. Spoiophoi, - 

 w ..... ly and very hard, at first hairy luit later smooth, dark. 

 and cracked; in form they are tuberous or triangular. In- 

 ternally they show no stratification. The fungus is very common 

 on living plum where it causes undoubted injury: it also occurs 

 on horn bean and aspen. 



Polyporus fulvus var. Oleae Scop. In northern Italy 

 may be frequently observed a peculiar splitting of the stems 

 of olive trees into two or more portion.-: the fissures occur 

 -enerally on the lower parts of the tree, and may extend so 

 deeply that tin- stem appears to stand on stilts or prop-. 

 Hartig 1 ascribes this phenomenon to the presence in tin- olive 

 stems of the mycelium of /V//y/</,-/'x j'nlni* causing n.tien places 

 whieh are eut out by the Italian cultivator-: bhe disease, how- 

 ever, ' ontinuing to make progress, it may be necessary in coi 

 of time to cut 80 deeply into the stem, that trad.- extending 

 ri'jlit through may be removed : this takes place all the more 

 rapidly if several disea-ed spots are bein- simultaneously 

 operated on. The de-tnictinn of the oli\e-\\oo, | by this parasite 



-imilar to that produced by /'. i<jni<i fin* on oak and other 



trei The -jporoplioie- appeal- on Miteii spots, but a iv gener- 



ally quickly removed by the ndtivator. Infeetion lake- plaee on 

 Wounds, hence it i- advi-able at once to apply tar after cut t in- 

 out any decayed wood, and al.-o to pain! priming-cuts or other 

 exposed surfaces with tar. Neighbouring fruit-tree-, liable to 

 suffer from this same fungii-, should be similarly treated, both 

 for their own -afety and that of the oli\e tree-. 

 Polyporus Fomes Hartigii . \lle-i her i /'. / 



I!, lluli-. !>] >|i.iltiui'_' 'l'-r ( )i-lli.iiiiiM . /' 



1893. 



-' 1;. ll.niij, /.! heinunyen, I'l. \"II. /',,,'/!. /,. 



tehrifl, 1893, \<. til. 



