THIELAVIA. 183 



The fungus has been observed on Lupinus angustifolius, L. alius, 

 L. thermis, Triffonella coerulea, Ondbrychis Crista galli, Pisum 

 sativum, Senecio elegans, and Cyclamen} 



Thielaviopsis ethaceticus Went.^ has been given as the cause 

 of a sugar-cane disease in Java. 



The Tuberaceae form a third sub-division of the Perisporiaceae. 

 The group includes the Tubereae and the Elaphomycetes. It 

 contains no forms injurious to plants. 



In investigating Maphomyces granulatus and ^. variegatus, 

 Eeess^ found that it not only formed mycorhiza, but vras also 

 parasitic on the roots of Pinus and destroyed them. 



PYBENOMYCETES. 



The ascocarp or perithecium of the Pyrenomycetes is a closed 

 structure provided with an opening by which the ascospores 

 are discharged. The ascocarp of the Perisporiaceae, as has 

 already been pointed out, has no such opening. The inner wall 

 of the perithecium is clothed with (a) the asci, {h) delicate fungal 

 filaments. Of the latter, those in the depth of the perithecium 

 are known as paraphyses, and among them the asci originate ;. 

 others around the sides and opening of the perithecium are 

 the periphyses, which grow inwards so as to close both pore 

 and canal. Perithecia may occur isolated or massed together, 

 and are frequently sunk in a special cushion of fungoid tissue, 

 the stromata. 



The Pyrenomycetes may also produce chlamydospores and 

 various forms of pycnoconidia and free conidia ; these also are 

 frequently developed on special stromata. According to Brefeld's 

 researches, the structures so well known as spermogonia with 

 their contained spermatia are only pycnidia containing conidia, 

 which have in many cases been artificially caused to germinate. 



The Pyrenomycetes include a large number of forms par- 

 asitic on all parts of living plants, most of them are capable 

 of existing for some part of their lives as saprophytes, and as 



^This fungus is described as causing a, root-rot of Viola odorata in U.S. 

 America {Connect. Agric. Exper. Stat. Report for 1891). (Edit.) 



2 Went, Archief voor de Java-SuiJcerindttstrie. 1893. 



^ Reess and Fisch. , "Untersuch. lib. Ban u. Lebensgeschichte d. Hirschtruffel." 

 Bibliotheca botan. Heft 7. 1887. With lUus. 



