Feb., 1909.] The Classification of Plants, IV. 447 



Protomycetae. 



3. Schizomycetae. Bacteria. 1350 species. 



Simple unicellular or filamentous fission fungi, parasitic, 

 saprophytic, or holophytic ; commonly with flagella or ciha, 

 sometimes moving by means of cell contraction; often producing 

 nonmotile spores which can endure great extremes of heat and 

 cold; reproduction by simple fission, the divisions in one, two, 

 or three directions; cells not naked or ameboid. 



4. Myxoschizomycetae. Slime Bacteria. 20 species. 

 Unicellular fission fungi with a sHght undulatory motion pro- 

 duced bv the contraction of the cell, imbedded in a pseudo-plas- 

 modium and moving about en masse; forming peculiar sporan- 

 gium-like bodies when passing into the resting or spore stage ; 

 cells not amoeboid ; saprophytes on decaying organic matter. 



5. Myxomycetae. Slime Moulds. 400 species. 

 Unicellular nonsexual mostly terrestrial fungi showing some 



relationship to the Rhizopoda, occurring in plasmodial masses of 

 more or less completely fused amoeboid cells which finally, with 

 few exceptions, build up complex sporangia-like bodies contain- 

 ing the spores or encysted individuals; spores on germinating 

 giving rise to flagellate naked cells ; saprophyts or rarely parasites. 



6. Archimycetae. 200 species. 



Simple parasitic often aquatic fungi without or with a very 

 imperfect mvcelium; nonsexual, with zoospores or with thick- 

 walled resting spores ; zoospores usually penetrating and develop- 

 ing in a cell of the host plant. 



II. NEMATOPHYTA. 57.000 species. 

 Gamophyceae. 



7. Protococceae. 230 species. 



Simple sextial green algae, single celled or in colonies; usually 

 with normal cells containing one nucleus; reproduction by divi- 

 sion, by free swimming gametes, or by motile spermatozoids and 

 stationary eggs. 



8. Hydrodictyeae, 26 species. 



Green coenocytic algae consisting of colonies of peculiar form 

 often very symmetrical; reproduction by the conjugation of equal 

 motile gametes ; nonsexual reproduction by zoospores which form 

 new colonies in the parent coenocyte or are discharged in a 

 delicate membrane. 



9. Diatomeae. Diatoms. 3000 living species. 



Single celled or somewhat filamentous algae usualh^ of a 

 brownish color, in which the cell wall becomes silicified and con- 

 sists of two valves usually with fantastic markings ; reproduction 

 by division or by the conjugation of two cells. 



