July is, 1914 
Fusarium on Sweet Potato 
261 
(Pl. XVI, fig. J) resemble those of Gibberella Saubinetii (PL XVI, fig. 0 ). 
The latter ascomycete has no chlamydospores, as pointed out by the 
writer (Wollenweber, 1913c, p. 31). This fungus did little damage on 
potato tuber in several inoculation experiments. Its more destructive 
nature as a cause of damping-off of oats and wheat (Wollenweber, 1913c, 
p. 31, 45) has been established by E. C. Johnson (1914). L. H. Pammel 
(1905) and others have repeatedly called attention to Fusarium culmorum 
as a cause of blight of wheat, barley, and oats in America. Schaffnit 
(1913, p. 612) described similar effects of the fungus on artificially 
weakened seedlings of rye. 
We cannot overlook the fact that students of the “Schneeschimmel” 
and foot disease of cereals are still endeavoring to appoint perfect stages 
for species of Fusarium. Voges (1913) illustrates two species of Fusa¬ 
rium on cereals which we easily recognize as F. metachroum App. 
and Wollenw. and F. culmorum and thinks he has proved the 
latter to be the conidial stage of Ophiobolus herpotrichus Fr. (Voges, 
1912). The present writer, however, has studied Ophiobolus in pure 
culture and grew normal perithecia on steamed stems of Eupinus and 
on straw. No sickle-shaped conidia developed in pure culture from 
any of the stages of the fungus, and no Ophiobolus appeared in pure 
cultures of any of the species of Fusarium associated in nature with this 
ascomycete. Voges's studies do not seem to be based on sufficient 
successful pure-culture work to withstand an unfavorable criticism of 
his conclusions. 
The writer was especially interested in the geographic distribution 
of Fusarium rubiginosum, a study begun in Dahlem. He mentioned 
(1911, p. 21) its occurrence on Zea, Triticum, and Avena. In the United 
States this fungus was sometimes isolated from Ipomoea, but its pre¬ 
dominant presence on many cereals seems to indicate its better adapta¬ 
tion to the Gramineae, especially to those grown in the warmer part of 
the Temperate Zone. These facts made desirable a second revision 
of the described species of Fusarium on cereals, as a result of which it 
was found that the name F. rubiginosum should give way to F. cul¬ 
morum. The illustration (Smith, 1884, fig. 92) leaves no doubt of its 
identity with this species. It has also been found in France, where 
Delacroix called it F. Schribauxii. Mattirolo (1897), in his interesting 
studies on Cerebella, seems to have worked with the same fungus. He 
calls it F. corallinum Sacc., but illustrates swollen conidia of F. culmorum . 
It may be noted that the name “Cerebella” refers to an old genus 
established by Cesati in 1851. Among the various fungi connected with 
this stage, Fusarium spp. play a part, and Mattirolo’s studies suggest 
that it is the pionnotes stage developed by some species which has 
caused the confusion with Cerebella. 
