108 C. D. Sherbakoff 



red even in a medium of an alkaline reaction. The observations of the 

 writer, so far as they go, are in full agreement with the above statements; 

 to which it may be added that certain fungi which in a neutral medium 

 produce a grayish white aerial mycelium (F. sclerotioides) , in the same 

 medium strongly acidified (0.4 per cent by weight of citric acid) produce 

 an aerial mycelium of a pink-vinaceous shade. 15 



It was observed also that acidity of the medium lowers the rate of the 

 fungous growth and makes zonation of the colony more prominent and 

 closer. The retardation of the growth depends on the kind of acid (see 

 also Smith and Swingle, 1904:42, 48) and its concentration; different 

 Fusaria are not affected in the same degree, some tolerating more acid 

 than others (see also Lewis, 1913:238). 



THE GENUS FUSARIUM 



Appel and Wollenweber (1910:4-12, 23-61) present a very detailed, 

 critical study of the genus, with the following list of synonyms: 

 Atractium Link pr. p. (1809) 

 Fusidium Link pr. p. (1816 and 1825) 

 Fusisporium Link (1824) 

 Selenosporium Corda (1837) 

 Fusoma Corda (1837) 

 Pionnotes Fries (1849) 



The description of the genus Fusarium given by these investigators, 

 when other data presented by them are also taken into consideration 

 and using the terminology of Lindau (1905, 1908-1909), may be stated 

 in brief as follows: 



Hyphomycetes of Mucedinaceae-Hyalophragmiae, Hyalostilbacese-Phrag- 

 mosporae, and Tuberculariacese-Mucedinese-Phragmosporse groups, with 

 smooth, not appendiculate, mostly sickle-shaped, acrogenous, noncatenu- 

 late conidia. 



The genus as delimited by these authors was to include also forms 

 such as F. dydimum and F. Willkommi, with cylindrical, one-septate spores, 

 and bacilliform, one- to five-septate spores. 



The writer has not sufficient material on hand to warrant any change 

 in the above characterization of the genus; but in the course of this work, 



16 The medium used in the instance cited was potato hard agar plus 5 per cent of glucose. The cultures 

 were made in petri dishes. 



