MTXOMTCBTm. 



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. — Fuligo variant {^thalmm septieum of Fr.). a epore; d, c, spore-case 

 rupturing and permitting the protoplasmic contents to escape; of, rounded mass of 

 naked protoplasm escaptid from the spore-case; fi, /, ciliated swarm-spore or 

 zoospore stage; g, h, i, k, I, amosba stage; m, young Plasmodium. — AfLerPrantl. 



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 amceboid form ; 

 in this stage (called the swarm-spore) 

 it repeatedly divides by simple fission 

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

 swarm-spores, now destitute of cili.-i, 

 begin the reverse process of coales- 

 cing, two or more of them fusing into 

 a common mass ; the process may 

 continue until a new plasmodium is 

 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 



Fig. 143. — Swarm-sporos of 

 CliondrioUerma di;fforme 

 (Didnmiiim Liieriianum of 

 De Bary) undergoing fission. 

 X 390.— After De Bary. 



