MTXOMTCETES. 



209 



into a large number of minute rounded bodies, the spores, 

 each of which is provided with a cell- wall. This latter is 

 called the spore-bearing stage, or simply the fructification of 

 the organisms. 



275. When placed under proper conditions of moisture 



Fig. 141. Fultffo variant (jEthaliwn septicum of Fr.). a spore; 6, c, spore-case 

 rupturing and permitting the protoplasmic contents to escape; grounded mass of 

 naked protoplasm escaped from the spore-case; e, f, ciliated swarm-spore or 

 zoospore stage; g, h, i, k, I, amoeba stage; m, young plasmodium. After Prantl. 



and temperature, the spores burst their walls, and the im- 

 prisoned protoplasm in each escapes and soon becomes a 

 motile, nucleated mass, provided with 

 a cilium, or having an amoeboid form ; 

 in this stage (called the swarm-spore) 

 it repeatedly divides by simple fission 

 (Fig. 142). After a day or two, the 

 swarm-spores, now destitute of cilia, 

 begin the reverse process of coales- 

 cing, two or more of them fusing into 



i nrimrnnn TTIQOO +lif> nrnpoea miv (Diduntiinn Libertianum of 



a common mass , i cess may De ary) aiH j erg0 j n g fission, 



continue until a new plasmodium is x 390 -~ After De Bary - 

 formed, differing from the first one mentioned only in size 

 (Fig. 141, a to m, and Fig. 143). (See Note on page 49.) 



276. The classification of the Myxomycetes is mainly 

 based upon the fructification, which usually consists of a 



