THE ASEPTIC CULTIVATION OF MYCETOZOA. 47 



uii sterilised hydrant water, the jar being covered by a glass 

 plate. On examining the culture ten or twelve days later 

 zoospores of plasmodia were found in the water, and sporangia 

 of Plasmodia developed on the hay a few days later, 



A number of similar cultures without aseptic precaution 

 were then made of hay gotten from different sources, and they 

 all showed the presence of plasmodia. 



Next a series of cultures were made in tall narrow beakers, 

 they being first closed with a large plug of cotton and sterilised 

 in a hot-air steriliser. The beakers were then filled about 

 half full with unsterilised hay. Care was taken to first wash 

 the hands and sterilise the scissors, so as to be moderately 

 certain that no spores of plasmodia were introduced from the 

 hands or instruments. Water which had been sterilised in 

 flasks was then poured into the beakers, until most of the hay 

 was submerged, care being taken not to cover it completely. 



In a few days the hay projecting from the surface of the 

 water was covered with mould fungi. A pair of sterilised 

 forceps was then used to remove the stalks of hay covered by 

 the fungi, care being used to loosen up the hay so as to have 

 some of it projecting above the water. If the hay is entirely 

 submerged plasmodia may not develop, but when prepared as 

 above, all of the cultures prepared with hay, whether gotten in 

 Heidelberg or Baltimore, developed plasmodia. It would 

 appear that plasmodia are constantly present on hay in one 

 form or another. 



Cultures prepared in the same way with the stalks of wild 

 carrot picked out from the hay did not develop plasmodia. 



A series of cultures were made by putting dried chestnut 

 and oak leaves in sterilised Erlenmeyer flasks with sterilised 

 hydrant water. In a number of these cultures plasmodia de- 

 veloped. 



Elsewhere (45) the writer has described the aseptic methods 

 employed in the cultivation of Protozoa, but for Mycetozoa 

 some modifications are necessary. They will grow in sterilised 

 dilute hay infusion, or 2 per cent, of milk in water, but for the 

 formation of sporangia it is in general advantageous, and for 



