General Features 295 



nutrient solution the gcrni-tubes soon develop into a branched 

 and septate mycelium which, after growing for two or three days, 

 gives rise to a new set of aerial hyphae which break up in their 

 turn into oidia. Sometimes, as shown in Text-fig. 10, the germ- 

 tube itself breaks up into oidia. 



"The germ-tube of an oidium readih' fuses with any other 

 hypha with which it comes into contact (Text-fig. 9). Thus such 

 a germ-tube has been observed to fuse with the germ-tube of 

 another oidium of the same or of opposite sex and with a h\'pha 

 of a mycelium derived from an ascospore of the same or of 

 opposite sex." 



Oedocephalum 



In a recent paper (M>cologia 29: 651) B. (). Dodge describes 

 "The conidial stage of Peziza pustulata." Twent\-five years ago 

 he noted the Oedocephalum stage of this fungus on a heated soil 

 extract agar, Ijut at that time it was thought to be of little 

 importance. So far as known no record of this was published. 



In June 1937, the writer made a fine collection of this species 

 in the woods east of the Museum Building of the Xcw York 

 Botanical Garden. At the request of Dr. Dodge this was turned 

 over to him for stud> . The species grows on burned spots and 

 charcoal, and is therefore referred to as a p\rophilous or fire- 

 loving species. Ascospores were planted on plates or cornmeal 

 agar and heated to a temperature of 58° for one hour, since 

 heating often stimulates the spore germination. 



Dodge states "Practically all the spores germinated. On the 

 second day characteristic conidiophores bearing heads of conidia 

 developed from the surface hyphae. The conidiophores (Fig. 22) 

 are usually about 150-350 n long, 3 or 4 celled, and end in an 

 Oedocephalum head which varies greath' in shape and size — 

 narrow clavate, oval to spherical 12-20 X 20-40 /i. Conidio- 

 phores may be much longer, sometimes even 1200 m long with 

 10 or 15 cells. 



"The conidia are very slightly colored and probably would 

 be described as hyaline with a slightly roughened or warted 

 surface, elliptical, 2.5-3 X 6-9 jj.. Some are larger, 4 X 12 yu. 

 The point where the conidium was originally attached usually 

 shows as a little papilla on the conidiophore head, and as a little 

 knob on the lower end of the conidium." 



