CHAPTER IX 



ACRASIEAE : AFFINITIES AND PHYLOGENY OF MYCETOZOA, &C. 



THE Acrasieae are a very small group made for organisms 

 which were formerly included in the Mycetozoa of de Bary. 

 In zoology they are termed Pseudo-plasmodida (Delage) to 

 distinguish them from the Euplasmodida or Mycetozoa 

 proper. They have also been called Sorophora. 



The only state in which they are visible to the naked 

 eye is when they have formed spore-clusters, which resemble 

 small mycetozoan sporaiiges : round, and about the size of 

 pins' heads, or, sometimes streak-like; they are white, red, 

 or yellow in colour. 



With the exception of Acrasis, which grows on the yeast 

 of beer, the known species live on decaying vegetable matter 

 and the dung of the horse and the cow. 



They begin their career by hatching from a spore-case 

 as amoebulae ; they do not develop a flagellum, but creep 

 like amoebae. 



They are depicted by Brefeld with short pointed pseudo- 

 podia. They have also a nucleus and a contractile vacuole. 

 Once hatched they multiply rapidly by simple division. 



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