56 CASPER 0. MILLER. 



The Time of the Appearance of the Large Plasmodia, 

 and of tlie Formation of the Sporangia. 



Plasmodia, as we usually find them in nature, appear rather 

 suddenly on decaying wood, tan, or leaves, and within a short 

 time they form sporangia. We know little about their pre- 

 vious growth. 



Some Mycetozoa may form sporangia during any of the 

 warm months, while, according to de Bary (21), others are 

 characterised by forming sporangia only during a short time 

 in the year. As has already been mentioned, Cienkowski 

 and Strasburger obtained sporangia on the fifth day after 

 planting the spores of Chond. diff., and Lister obtained 

 them in from ten to fourteen days. Celakovski (38) men- 

 tions that the sporangia of Steraonitis dictyospora, 

 llostaf., developed fourteen days after the appearance of the 

 Plasmodia, but does not state how long it took the plasmodia 

 to develop. 



Rex (36) mentions having seen Stemonitis Bauerlinii 

 form sporangia or) a decayed log iu the autumn, and the next 

 summer the same species formed sporangia three times on 

 the same log at intervals of a month. One cannot say that 

 the spores fell ])ack on the log, developed zoospores, and from 

 these new plasmodia grew and formed sporangia. 



In the cultures made with unsterilised hay in water the 

 conditions are practically the same. The forms of the Myce- 

 tozoa, whether microcyst, sclerotia, encysted zoospores, or 

 spores, have been dried for months. The hay is placed in the 

 water and kept at the room temperature. The sporangia of 

 Chond. diff. appeared on the hay from the twenty-fourth to 

 the twenty-ninth day. Crops of sporangia continue to be 

 formed on the hay every few days for from two to four weeks. 



Didymium micro carp on first show sporangia on the hay 

 from the twenty-first to the twenty-fourth day, and continue to 

 form sporangia for several weeks. 



When there were only a few stalks of hay projecting above 

 the surface of the Avater the sporangia appeared, but were less 



