294 PROCEEDINGS OF THE AMERICAN ACADEMY. 



thin mucilaginous film about each, eventually becoming a dry powdery 

 mass, completely concealing the mycelium, more or less spherical, 

 119-122 ,u in diameter, composed of closely compact angular cells, 

 150-200 cells visible in a surface view; cells homogeneous throughout. 

 Individual cells of the bulbil eventually forming spherical spores, 17- 

 22 fi in diameter loosely held together. No other spore-form known. 



On straw, old paper, from California and cotton flowers from Cuba. 



This fungus has been obtained from at least three different sources. 

 It was found by Dr. Thaxter running over a gross culture of the flowers 

 of Cuban cotton and also by the writer on gross cultures of barley straw 

 from Claremont, California, and on old paper from Duarte, California. 



The usual methods of obtaining a pure culture were employed here, 

 after which the fungus was grown on various kinds of nutrient material, 

 but it could not be made to produce any perfect form. Mycelia from 

 widely different sources were contrasted in Petri dishes but no results 

 were obtained except the production of certain abnormal enlargements 

 and contortions of the hyphae, such as may frequently be observed in 

 contrasting forms of even widely different species. 



The mycelium of this fungus is white, inconspicuous, procum- 

 bent, the hyphae densely filled with coarse granules or oil globules. 

 At a short distance from the margin of growth small white pustules 

 are seen, which gradually become larger and more frequent as they 

 approach the point of inoculation. These soon turn tan-colored, and 

 are frequently associated with small drops of liquid of nearly the same 

 color, which may often be seen surrounding a bulbil. At maturity 

 these bulbils are almost spherical, 1 19-122 /x in diameter, composed 

 of closely compacted angular, often irregular cells, uniform throughout, 

 there being no distinction of a definite cortex. They occur in large 

 numbers heaped together, covering the whole substratum and obliter- 

 ating completely the naturally scanty mycelium. In older cultures 

 they become a dry powdery mass. 



The bulbils. — The formation of this bulbil is different from that of 

 any of the others thus far considered, since they result not from the 

 development of a single primordium but from the combined activities 

 (if several primary branches. One or more procumbent hyphae send 

 up vertical branches which twine about each other (Figures 1-4, 

 Plate 11). Usually several of these branches arise simultaneously at 

 a given point (Figure 3, Plate 11) and as the bulbil increases in 

 size, more and more of these take part in its formation, their extremi- 

 ties combining to produce the bulbil proper, while just above the 

 substratum there may form a sterile supporting base, often with a 



