414 



A TEXTBOOK OF BOTANY 



[Ch. X 



they form a new Plasmodium. Morphologically, therefore, 

 the Plasmodium is a kind of colony, in which the individual- 

 ity of the original members has become completely merged. 

 The plasmodia reproduce also in other minor ways, notably 

 from separable hard fragments, or sclerotia, which, on ac- 

 cess of water, produce new plasmodia. The most striking of 



I 



Fig. 283. — Sporangia and capillitia of various Myxomycetes ; the 

 smaller are somewhat less than natural size. (From Kerner.) 



all the Myxomycetes, in regard at least to its Plasmodium, 

 is JEthalium septicum. Its favorite home is old tan bark 

 (whence its name "flowers of tan"), and its yellowish 

 slimy Plasmodium often reaches a foot in diameter, though 

 the spore formation is inconspicuous. Mostly the group 

 has no particular economic relations to man's interests, but 

 one parasitic form produces the damaging "club root" of 

 cabbage. 



