Jehangir Fardunji Dastur 255 



Even in single-spore cultures some acervuli show many setae, others a 

 few and still others none. 



Colletotrichum nigrum E. and Hals. 



The acervuli of C. nigrum E. and Hals, on chilli fruits collected in 

 Burma and in Pusa are quite similar to those of G. piperatum E. and E. 

 already described, except that in the acervuli of the former there is a 

 development of stiff, erect dark brown setae, which measure up to 150)u. 

 long and ifj, broad. 



In December 1918, a chilli fruit was found in Pusa attacked by 

 C. nigrum. The acervuli were carefully examined under a binocular 

 microscope and all of them, without exception, were found to have 

 developed setae. Four series of cultures from this diseased fruit were 

 started on glucose-meat-extract-agar. 



1. A single conidium was planted on the medium. 



2. A diseased seed was aseptically removed and transferred to the 

 medium. 



3. It may perhaps be suspected that the fruit might have been 

 infected with G. piperatum E. and E. as well, the acervuli of which had 

 escaped detection under the microscope, that the single conidium might 

 have been taken from a Gloeosporium acervulus and that in the tissues 

 of the diseased seed both Gloeosporium and Colletotrichum hyphae might 

 be present. To be sure that only C. nigrum was really taken in culture 

 a single seta was picked off and planted on the medium. 



4. The infected fruit was incubated and in less than a week a thick, 

 black, undulating crust was formed where there were originally acervuli 

 of C. nigrum. In this crust were found perithecia. A single ascus was 

 transplanted on the medium. (This development of the perfect stage is 

 similar to that already described in the case of G. piperatum.) 



A fifth series was at the same time started, for comparison, from a 

 single ascus got from a fruit originally attacked by G. piperatum E. 

 and E. and which had developed the ascogenous stage on incubation. 



At room temperature, which ranged between 62° to 68"^ F., the growth 

 in all these five series of cviltures was alike. The mycelium. was matted 

 and confined to the substance of the medium and at first the colour of 

 the mycelium on the surface of the slant was distinctly pink, but there 

 was no development of conidia except in the culture started fiom a single 

 seta, Ser. 3rd; there were no setae in this culture. The pink colour was 

 soon replaced by black or greenish black. In a week's time tho surface 

 of the medium was covered by a thick undulating black crust, punctuated 



