120 C. D. Sherbakoff 



observation of all the stages, it will be possible to pick out easily the 

 typical and normal one and base judgment mainly on that. Most minute 

 attention must be paid to the shape of macroconidia. 



In order to avoid much of the possible confusion in regard to the color 

 production by the fungi, it will perhaps be not out of place to mention 

 again that a convenient standard of colors must be used. Ridgway's 

 (1912) color standards have been used in this work. 



IDENTIFICATION OF THE FUSARIA WITH PREVIOUSLY DESCRIBED 



SPECIES 



An identification of the Fusaria of potatoes with Fusaria formerly 

 described as occurring on other substrata and even on potatoes, is in 

 most cases impossible or at least rather doubtful. The species have been 

 described mostly from material as it was collected in nature. After 

 what has been said in the foregoing pages about variability of the Fusaria, 

 about their common occurrence in different, often abnormal, stages, 

 about the necessity of most minute attention to the peculiarity of the 

 shape of the macroconidia, and about the importance of good drawings 

 and of measurements properly made and presented, it can easily be seen 

 what small chance there is of identifying an organism from any typical 

 description of one of these species. The figures are often absent, and 

 when present they are either too schematic or so inaccurate that they 

 might just as well be omitted. Any citation in support of this statement 

 would be superfluous. 35 



There are a number of different Fusaria which agree with a certain 

 description and therefore might be considered as the same species. At the 

 same time the very same organism may have other characters which, 

 if studied alone, would surely set it off as a distinct species. An extensive 

 illustration of this state of affairs is given by Appel and Wollenweber 

 (1910:9-12), but the most impressive case is that of Smith and Swingle 

 (1904:50-51). Therefore, although the literature on the subject was 

 fully examined, especially publications of descriptions supplemented by 

 any kind of illustrations, usually no definite conclusion in regard to identity 

 could be arrived at. Because of this, and also because the most important 

 literature is already listed in a few works on this subject (especially by 



35 Appel and Wollenweber (1910: 12) in this connection made the following statement: " Oft blieb una 

 daher weiter nichts iibrig, als neue Namen zu geben und ihnen so genaue Beschreibungen beizufiigen, 

 dass nunmehr die Arten immer wieder erkannt werden konnen." 



