431 



mr^r^^ 



''MM 



The very characteristic destruction of oak-wood caused by 

 this fungus was investigated by II. Hartig. The diseased wood 

 has a uniform dark-brown colour, broken at intervals by white 

 rounded spots or hollow cavities ; 

 lience it receives the name of 

 " partridge-wood." In the white spots 

 the wood has by the action of the 

 mycelium become transformed into 

 cellulose, the middle lamellae and 

 starch-grains being dissolved out. In 

 the neighbourhood of old eaten-out 

 cavities the process of decomposition 

 is slightly changed, so that the cell- 

 walls disappear without previous trans- 

 formation into cellulose. 



CLAVARIEAE. 



Typhula. 



Sj )( irophores tilanientous, 



and, as 



a rule, developed from sclerotia. 

 Basidia, with four colourless smooth- 

 coated sjjores. 



Typhula graminum Karst.^ This 

 a])peared on wheat plants in Sweden, 

 killing them and forming yellow 

 sclerotia {Sclerutium fidvurn Fr.). 



stulosum. 



Later stages of Oak-wood destruc- 

 tion. Longitudinal section showing,' 

 lioles in the timber, (v. Tubeuf 

 l.hot.) 



HYDNEAE. 



Hydnum. 



Sporophores very variable in form and structure. The 

 hymenial layers are spread over teeth-like projections. The 

 basidia bear four wlnte spores. 



Hydnum diversidens Fr.- (Britain). The sporophores foiiu 

 yellowish-white crusts or brackets, with spiny outgrowths on 

 the lower side. The hymenial layer consists at first of l)asidia 

 only, later, however, hyphae grow up througli it and build 



' Eriksson, Laiidtbr. Akad. Hand. v. Tidskr., 1879. 

 - R. Hartig, Zerselzungserscheinuii</e7i. 



