no Transactions British Mycological Society. 



through wounds with a pure culture of the fungus, but beyond 

 a strictly limited growth at the expense of the cells injured in 

 making the wounds, no development occurred, and no trace 

 of any kind of rot was set up. Since, however, the fungus was 

 found occasionally on stalks not completely dead there may 

 possibly be special conditions under which it behaves as a 

 parasite or at least a feeble parasite. 



After the above described study of C. tabifiomn had been 

 made a paper was published by O'Gara* in which a new species 

 of Colletotrichum (C. solanicolum) occurring on potato stalks 

 was described. An attempt to obtain a culture of this species 

 failed, but judging from the published description it is just 

 possible that it may be identical with C. tahificuni. 



The setae in the latter appear to be longer and the conidia 

 rather longer and narrower than in C. solanicolum, but too 

 much stress must not be laid on these somewhat variable 

 characters. Perhaps the most striking point of difference is 

 that, although O'Gara grew his fungus in pure culture, he 

 does not mention the development in the medium of any 

 amethystine fluorescence such as is so characteristic of C. 

 tabificum, and which he would scarcely have failed to observe 

 had it been present. Nor, apparently, was the mass of spores 

 borne by the acervuli of this colour. There appears to be some 

 doubt as to whether C. solanicolum is parasitic or not, for no 

 inoculation experiments are reported. But the fungus is 

 stated to have been found on living as well as on dead potato 

 stalks. No amethystine coloration of the pith of affected 

 stalks was noted. 



Taubenhausf has also described a Colletotrichum, derived 

 from potato tubers, which he regards as being identical with 

 C. solanicolum. On priority grounds, however, he maintains 

 that it should be called C. atramentarium since he regards this 

 fungus as being equivalent to Frank's Phellomyces sclerotio- 

 phorus and this, in turn, to Berkeley and Broome's Vermi- 

 cular ia atramentaria. 



Those of us who are familiar with the sterile P. sclerotiophorus 

 and its fructifying stage Spondylocladium atrovirens, both as 

 it occurs on the potato tuber in Europe and as it behaves in 

 pure culture, will perhaps not readily concur in this view. 



In his primary isolation experiment Taubenhaus obtained 

 three fungi from the surface tissue of a potato tuber affected 



* O'Gara, P. J. New Species of Colletotrichum and Phoma. Mycologia, vii. 

 1915. P- 38. 



f Taubenhaus, J. J. A contribution to our knowledge of Silver Scurf 

 (Spondylocladium atrovirens Harz) of the white potato. Mem. New York 

 Bot. Gard. vi. 191 6, p. 549. 



