THE NORTH AMERICAN 

 SLIME-MOULDS 



THE MYXOMYCETES (Link) DeBary 



Chlorophyl-less organisms whose vegetative phase consists of a 

 naked mass of multinuclear protoplasm, the Plasmodium; reproduced 

 by spores which are either free or more commonly enclosed in 

 sporangia, and which on germinating produce ciliated or amoeboid 

 zoospores, whose coalescence gives rise to the Plasmodium. 



The Myxomycetes are, — 



A. Parasites, in the cells of living plants . . . PHYTOMYXiNiE 



B. Saprophytes, developed in connection with decaying vegetable matter: 



a. With free spores ExosPOREiE 



b. With spores in receptacles or sporangia . . Myxogastres 



Sub-Class PHYTOMYXIN^ Schroeter 

 1889. Phytomyxinae Schroeter, Engl. u. Prantl., I., i., pp. 1 and 5. 

 The parasitic Myxomycetes affecting plants include but few (four 

 or five) species, distributed among four genera. All are parasites in 

 the cells of particular hosts; their vegetative phase is plasmodial and 

 their spores are formed by the simultaneous breaking up of the Plas- 

 modium into an indefinite number of independent cells. But a single 

 genus need here concern us, — 



Plasmodiophora Woronin 



1879. Plasmodiophora Woronin, Pringsh. Jahrb., XI., p. 548. 



Parasitic in the parenchymatous cells of the roots of living plants, 

 causing noticeable enlargement of the affected organ, producing at 

 length galls, knots, and various deformities and distortions. Spores 

 spherical, smooth, colorless, 16 /-i. 



3 17 



