Damping Off. 333 



did not present at the time a dark color as is the case with the com- 

 mon carnation anthracnose, Volutella dicmthi (Hals.). At the 

 time it was supposed that this lack of color in the setae might be 

 due to the growth. Sections of the stromata showed the structure 

 of a Volutella, but the conidia were considerably smaller than those 

 of V, diantJii and the setae were quite different in form as well as 

 in color. They taper but little toward the free ends, are quite blunt 

 at the ends and usually more times septate. 



At my request Mr. R. H. Pettit, a student in my laboratory, 

 made a separation of the fungus for me by the agarplate method. 

 The first trial was successful and in a few days the colonies of the 

 Volutella were visible to the unaided eye, the conidia having been 

 kept watch of during the stage of germination and the formation 

 of the colonies. The growth of the colonies is quite diffeuent 

 from that of the Y. dianthi as well as the development of the 

 fruiting hyphae, and there was no longer any doubt that it was 

 a different species from the V. dianthi, SLud the name V. leucotricha 

 is here proposed for it. 



Pure cultures were then started on bean and vetch stems and in a 

 few days the characteristic stroma with the setae were developed 

 in profusion on the surface of the stems. With the conidia from 

 one of these cultures pure dilution cultures were made on April 20th. 

 Instead of pouring a few drops of the first dilution into the second 

 and from this into the third as I usually do with fungi having large 

 conidia, the second and third dilutions were made by transferring 

 with a double and twisted platinum needle. Plate No. 1 and 54 

 were sutficiently separated for the study of colony characteristics 

 and for photographing natural size. The colonies grow rather 

 slowly and the plate No. 2 was ready for photographing on the 

 25th, and No. 3 on the 27th. In No. 2 the colonies were quite 

 numerous and consequently rather small, from 4-6 mm. in diameter, 

 while those in plate No. 3 where there were only 6 colonies were 

 on the 27th 10 mm. in diameter. The colony steadily develops a 

 thin and nearly circular weft marked by numerous fine radiating 

 lines which because of the exceeding thinness of the weft are visible 

 over the entire colony as it ages. There are quite regularly more 

 dense radiating lines caused by the overlaping of certain radiating 

 areas, and the margin shows a tendency to form roundish angles. 

 The growth is quite sensitive to periodic changes in temperature 

 which occur between night and day, as shown by the several con- 



