Some Saprophytic Fungi of Potatoes. G. H. Pethybridge. 107 



and the paraphyses are shown in more detail in Fig. 5, while 

 Fig. I illustrates ripe and unripe ascospores and Fig. 2 shows 

 ascospores germinating. 



As regards nomenclature, the combination Ncctria cinna- 

 barina cannot, of course, be adopted, since this name is already 

 in use for the well-known "Coral Spot" fungus. Since the 

 perithecia were discovered more or less by accident the specific 

 name inventa does not seem inappropriate. The characters 

 of the fungus may be summed up, as follows: 



Nectria inventa Pethybridge. 



Peritheciis gregariis, globosis, atro-rufis, superiore parte 

 pilosis, 300-500//. diam., paraphysibus filiformibus dein obsoletis, 

 3-4JL1 X 150/x; ascis cylindricis, vel cylindraceo-clavatis, 

 60-100^ X 4-6 /x, octosporis ; sporidiis monostichis, oblongis, 

 hyalinis, i-septatis, 4-5 /a x 9-iOjU,. 



Hab. In tuberibus putresc. Solani tuberosi in Hibernia. 

 Status conid. sistit Vcrticillii cinnabarini R. et B. (Acro- 

 stalagmi cinnabarini Corda). 



Inoculations with pure cultures, through wounds into living 

 potato stems and tubers, did not result in any sort of infection ; 

 hence the fungus is a saprophyte, so far as the potato is con- 

 cerned at any rate. Control inoculations into stalks of healthy 

 growing potato plants were made at the same time with a 

 pure culture of Verticillium albo-atrum R. et B. and hadromycosis 

 was set up in each case. 



II. COLLETOTRICHUM TABIFICUM. 



(Syn. Rhizoctonia tabifica Hallier.) 



In a paper published in 1875 Hallier* attributed the disease 

 in potatoes known as "Curl" to the presence (chiefly in the 

 pitted vessels of the wood) of a parasitic fungus which he 

 named Rhizoctonia tabifica. Of course no cultures of the 

 fungus were made, nor were any infection experiments carried 

 out, and a critical study of the paper leaves no doubt in one's 

 mind but that Hallier was dealing with at least two (if not 

 more) distinct organisms. It is highly probable that the princi- 

 pal one of these was the fungus Verticillium albo-atrum, described 

 later by Bertholdf and Reinke, investigated more fully by the 

 present authorj still more recently, and shown to be the cause 



* Hallier, E. Die Ursache der Krauselkrankheit. Zeits. f. Parasitenkunde, 

 iv. 1875, p. 97. 



f Loc. cit., p. 67. 



X Pethybridge, G. H. The Verticillium Disease of the Potato. Sci. Proc. 

 Roy. Dublin Soc. xv. (N.S.), 7, 1916, p. 63. 



