188 NEW SUGARCANE DISEASES 



hollows of the pith. As a rule, so far as has been observed, the 

 infection is not virulent ; spread within the cane is gradual and 

 communication from one plant to another slow. A large number 

 of borer holes become infected late in the season, but the parasite 

 usually seems to remain confined to a few internodes. As bored 

 setts are usually discarded at planting time, infection by this 

 channel is not often transmitted to the following crop. The 

 fundus has not been found on the leaves or on the surface of the 

 stem, in the field. In the laboratory, however, a case of sponta- 

 neous infection of the leaf with a fungus exactly resembling that 

 under consideration occurred, and this led to further examination. 

 Inoculations were made with cultures obtained from the growth 

 on the leaf and also with cultures from diseased cane stems. 

 Both ijave similar results. Six inoculations were made with each 

 of the two cultures. In two cases the inoculated leaf withered 

 too rapidly to allow of definite observations. The remaining ten 

 were quite successful, PI. II, Fig. 1, showing the condition after 

 three days. Penetration had occurred chiefly through the large 

 thin- walled motor cells. We have not been successful in finding 

 cases of leaf infection in the field, but as leaf spots are extremely 

 common on sugarcane such a search is not easy. The spot caused 

 by Ce2:>halosporiimi Sacchari in artificial inoculations resembles 

 that caused by I felminthosjjoriiwi Sacchari, described in a later 

 section of this paper, and all the field cases examined belonged to 

 this latter fungus. 



Rotten canes must set free large quantities of spores and the 

 source of the infection of cane wounds may come from these, from 

 the leaves and, if the species passes part of its life as a soil sapro- 

 phyte, as is not improbable, po.ssibly also from the soil. The genus 

 is so common in cultivated soils, and this species has so little to 

 distinguish it from some of the habitual soil dwellers, that its 

 recognition would be difficult. It lives very readily as a sapro- 

 phyte, however, growing luxuriantly on most of the common 

 culture media and remaining alive in culture for about o months, 

 so that it is probably present in the soil of cane fields. The 

 inoculation experiments indicate tliat infection of the setts at the 



