STEREUM 395 



bark of the main stem peels off in large flakes. On the tea 

 plant the fungus first appears on the smaller twigs and 

 gradually spreads down to the thicker branches, where it is at 

 first quite superficial, but the hyphae gradually penetrate and 

 kill both bark and cambium. In the majority of instances 

 the pink incrustation is permanent, but when old it cracks 

 into lines more or less at right angles to each other, and loses 

 its pink colour, fading to ochraceous or almost white. Some- 

 times the fungus causes the bark to die off in patches, which 

 afterwards form cankers that enable other species of fungi to 

 gain an entrance into the tissues of the host. 



C. Zimmermannii, Sacc. and Syd. (=C.javanicum, Zimm., 

 now C. javanicum, Sacc. and Syd.). Membranaceous, some- 

 times broadly effused, flesh-colour or yellowish, loosely 

 adhering by hyphae to the matrix, basidia clavate, 4-spored. 

 sterigmata slender, 4-6 /u, long; spores piriform, apiculate, 

 hyaline, 9-12x6-7 /*. 



Fetch, T., Circ. and Agric. Journ. Roy. Bot. Gard.^ Ceylon, 

 vol. iv. No. 21, July 1909. 



STEREUM (PERS.) 



Furnished with a central stem, dimidiate or entirely resu- 

 pinate, hymenium even, originating from a compact sub- 

 hymenial layer ; spores hyaline or tinted ; basidia tetrasporous. 



Differs from Cortidum in the distinct subhymenial layer. 



Stereum wood rot (Stereum hirsutum, Fries.) is one of our 

 commonest of saprophytes, growing on dead trunks, stumps, 

 etc. Hartig has shown that not infrequently it lives as a true 

 and very destructive parasite on different kinds of broad- 

 leaved trees. It is a wound-parasite, and the mycelium having 

 gained access to a living tissue, continues to extend until the 

 whole is destroyed. Wood that is attacked becomes pale 

 brown first, then changes to yellowish-white. The thickening 

 of the cell-walls is first dissolved and used by the fungus, the 

 intercellular plates alone remaining, and these are eventually 

 dissolved. Ward studied this fungus, and added considerably 

 to the account previously given by Hartig. He also succeeded 

 in growing the fungus as a pure culture, from the spore to the 

 sporophore. 



