On a New Species of Melanotaeninm. Rudolph Beer. 333 



the distribution of the spores in the tissues of the host plant. 

 In Entyloma the spore-masses are hmited to small pustular 

 swellings of the leaf or stem whilst in Melanotaenium the spores 

 are spread over a wider area of the host tissues. In Entyloma, 

 moreover, the spores germinate whilst they are still enclosed 

 within the tissues of the host, whilst in Melanotaenium germina- 

 tion only takes place after the decay of these tissues. 



In the case of the present fungus the spores are often spread 

 over wide areas of the stem or leaf, whilst with regard to the 

 question of their germination, although, as already mentioned, 

 this has not been actually observed either in the tissues of the 

 host plant or in artificial cultures, yet indirect evidence regard- 

 ing the situation of their germination is obtained from the 

 following experiments. 



A series of inoculations were carried out on 15th May, 1919, 

 in which ungerminated spores derived from completely decayed 

 intumescences were transferred to small wounds made in healthy 

 plants by means of a sterilised scalpel. * ' 



Most of these were unsuccessful but in the case of one plant 

 examined on the following September it was found that the 

 characteristic swellings had developed upon the subterranean 

 shoot in close proximity to the point of inoculation. The plant 

 inoculated had been obtained from a district in which the disease 

 was unknown and it was in all respects perfectly healthy. Care 

 had been taken to ensure that the soil in which the plant was 

 grown was uncontaminated. 



From these observations it may be concluded that the spores 

 of the fungus do not germinate whilst still within the tissues of 

 the host but only after these tissues have decayed and favour- 

 able conditions for germination have been established. It will 

 be seen, therefore, that in both the features which were men- 

 tioned above as distinguishing Melanotaenium from Entyloma 

 the present fungus is in agreement with the former genus. The 

 fungus is named and described upon a later page of the present 

 paper (see p. 337), 



The Genus Melanotaenium. 



The genus Melanotaenium was established by de Bary (1874) 

 who sorted out and rearranged the heterogeneous series of forms 

 which had hitherto been grouped together under the names of 

 Protomyces and Physoderma. Some he retained in these genera 

 and others he referred to Entyloma, whilst one form, discovered 

 by Unger (1833) and named by him Protomyces endogenus, he 

 placed in a new genus, Melanotaenium, which he believed, quite 

 correctly, to have its closest afiinities with the Ustilagineae: 

 M. endogenum is parasitic upon the stems and leaves of various 



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