HOTSOX. — CULTURE STUDIES OF FUNGI. 279 



from New York State, produced several different kinds and among 

 them P. coprophila which has been secured from at least ten differ- 

 ent sources, not only on onions, but frequently on horse dung and 

 straw. It grows readily on potato and bran agar, but, like many of 

 the other species, after continued artificial cultivation the mycelium 

 becomes scanty and the bulbils few. In such cases it can be re- 

 juvenated by growing on a gross culture of sterilized fresh horse dung, 

 on which the mycelium is developed luxuriantly and becomes floccu- 

 lent, producing bulbils and conidia abundantly. 



This species appears to be the same as that described by Zukal ('86) 

 under the name of Helicosporangium coprophilum which he found 

 growing on horse dung. The general appearance of the bulbils of 

 these two forms, their size, color, and at least one phase of their 

 development seem to be identical. The form under consideration, 

 however, differs from the description given by Zukal in producing a 

 copious supply of flocculent hyphae. This may be due to the differ- 

 ences in the conditions of cultivation. P. coprophila resembles in 

 mode of development the species referred by Eidam to Helicosporan- 

 gium paras iticum Karsten, but the bulbils of the latter are brick-red, 

 with yellowish cortical cells which, judging from the figures, are much 

 less prominent than in the present form. The only other close allies 

 are P. parasitica and P. spinulosa, the former easily distinguished by 

 its single large central cell, the latter by its mode of development, 

 and the presence of slight thickenings in the walls of the cortical cells. 



This form develops sparingly on very moist substrata. On nutrient 

 potato agar containing sugar, however, or on fresh horse dung, it 

 grows well. Contrast cultures of 'mycelia from different sources 

 yielded nothing more than additional variations in the filaments and 

 bulbils. The former grew much more luxuriantly at the points of 

 contact of the two sets of mycelia. 



The bulbils. — A short lateral branch coils up, making about one or 

 one and a half turns, the end cell enlarges, becomes spherical and 

 frequently turns brownish. As it continues to increase in size its 

 two lateral faces protrude more or less conspicuously and may even 

 become subpendent, as in P. parasitica (Figure 4, Plate 5). These 

 projections, however, often behave differently from those of the 

 latter, since they are frequently cut off and thus form other enlarged 

 central cells. Sometimes the second or even the third cell of the coil 

 enlarges and takes part in the formation of the central cells. Those 

 that do not enlarge grow out laterally over the surface of the central 

 eell or cells and eventually completely enclose them. Figures 13-15, 



