28 BULLETIN 1053, IT. S. DEPARTMENT OF AGRICULTURE. 



normal conditions of growth, and their formation is independent of 

 environmental conditions. They germinate immediately and nor- 

 mally, are formed in loose dustlike masses, and are easily removed. 

 The former he considers a facultative transition form and the lat- 

 ter a true propagative form. 



Hotson in two papers (22 and 23) extended and summarized our 

 knowledge of bulbils and similar propagative forms, and added the 

 finding of bulbils in a few basidiomycetes. Learn (28), in his cul- 

 tures of Pleurotus ostreatus, noted the formation of new mycelial 

 growths at the base of wood-block cultures below blocks bearing 

 oidia. This suggested the shedding of these oidia from above. Weir 

 (62) noted a Ptychogaster form in connection with Trametes 

 suaveolens growing naturally, and he remarks that in the damp 

 woods of Idaho there are many abnormal polyporoid forms, some 

 of them conidial. In Forties officinalis, Faull (18) found chlamydo- 

 spores not only in cultures but also in the crust of the sporophores. 

 The writer has found the chlamydospores of this fungus on rotting 

 wood in nature (55). Hiley (20) reviewed the status of the conidia 

 of Fomes annosus. 



REFERENCES TO THE OCCURRENCE OF SECONDARY SPORES IN NATURE. 



The references to secondary spores occurring in nature are quite 

 numerous. Perhaps the least understood of the fungi producing 

 secondary spores are the Ptychogasters, which are considered ab- 

 normal conidial or chlamydospore fructifications of -the polyspores. 

 Observations on the Ptychogasters occur chiefly in the older litera- 

 ture, and reference may be had to Boudier (3 and 4), De Seynes (50, 

 51, 52, 53, 54), Richon (48), Ludwig (30), Patouillard (42 and 43), 

 Brefeld (5), and "Weir (62). Then there are the spores reported as 

 conidia, called "wet- weather spores" by Lyman (31, p. 135), who 

 said that until these spores had been more thoroughly investigated 

 their nature must be regarded " as uncertain and their occasional 

 production as of doubtful importance to the fungus." (Cf. Patouil- 

 lard, 41, 44, 46\ Eichelbaum, 11 ; and Massee, 33.) Of the references 

 to secondary spores in nature the status of which is more certain, 

 we might mention the following: Chlamydospores on the hairs of the 

 stipe of Pleurotus ostreatus (Patouillard, 39) and in the hymenium 

 (Matruchot, 34) ; chlamydospores in groups or singly in Trametes 

 rubescens (Daedalea confragosa) (Patouillard, 40) ; chlamydospores 

 in fruit bodies of Polyporus sulfureus (De Seynes, 50, 51) ; conidia 

 (chlamydospores according to Lyman, 31, p. 136) in the hymenium 

 of Ilydnum coralloides (De Seynes, 53) ; terminal chlamydospores 

 in Fistulina hepatica (De Seynes, 50) ; chlamydospores on and in the 

 pileus of Nyctalis asterophora and N. parasitica and conidia of Fomes 



