424 



BASIDIOMYCETES. 



cell-sap. Cells of the parenchyma in llower and stem enlarge to a 

 still greater degree. Intercellular spaces are as a rule obliterated, 

 but when present are filled with a fine mycelium. Wakker gives 

 us further results of the fungoid attack ; crystal-glands, normally 

 numerous, are no longer formed, but are replaced to some extent 

 by indistinctly defined crystals of calcium oxalate. Transitory 

 starch is stored up in large quantity. The fibro-vascular bundles 



Fig. •2.'iO. — Exohasidium vaccinii inducing outgrowths on leaves of Vorc'inium 

 Vitis-hUua. (v. Tubeuf phot.) 



present a striking modification, the primary xylem alone is 

 normal, the vessels of the secondary wood remaining rudimentary ; 

 other parts are not lignified, and the phloem is only indistinctly 

 laid down. 



A mycelium is present in all deformed parts, but absent in 

 normal green tissue. It becomes massed to form a hymenial 

 layer beneath the epidermal cells or between their outer walls and 

 the cuticle. The sterigmata do not exceed four in number, and 



