PLASMODIA OF BADI1AMIA UTRICULARIS. 383 



m odium indirectly by promoting the growth of filamentous 

 moulds, such as Aspergillus or Penicillium, which soon appear on 

 fungus or bread, after the mixture has been applied to it. The 

 hyphae of these moulds are dissolved and absorbed by the proto- 

 plasm as food. 



In using the mixture discretion must be exercised, according to 

 the condition of the plasmodium, as sometimes plain water is 

 preferable ; but the careful observer will find sufficient indications 

 to guide him in this respect. No precise rules can be laid down, 

 but the student will find that with these auxiliary helps he will 

 be less dependent than heretofore on a supply of Stereum or 

 similar fungus, although it may be advisable to use some of that 

 at times, if convenient, as being the more natural food. Any 

 fungus which becomes putrid must be removed, or it may poison 

 the plasmodium ; but the bread is not so liable to become 

 injurious, and may remain a reservoir of protoplasm until, after 

 a prolonged period, the plasmodium has eaten it all. 



]STote. I have also been asked to describe, for the benefit of 

 our readers, my method of exhibiting the reversing currents of 

 streaming plasmodia, a description of which has been given in 

 the Journal.* The very simple arrangement is shown in the 

 diagram below. 



Fig. 6. 



A tube of this size is sufficient, and a ring of blotting-paper, 

 with sclerotium upon it, is placed inside ; the sclerotium being 

 between the paper and the glass. A few drops of water are 

 added, the cork is inserted, and the tube is then tilted and 

 revolved until the water has soaked the paper and moistened the 



* Joum. Q.M.C., Vol. X., pp. 263-270, November 1908. 



