Mar., 1922 classification of plants 137 



34. Sperms biciliate; nonsexual spores absent; gametangia in sunken con- 

 ceptacles; plants usually flat or flattish, branched, attached below, medium 

 to large in size. (Cyclospor.^). Fucales. 



34. Sperms with one flagellum, nonsexual spores (tetraspores) nonmotile, repro- 



ductive organs external; fronds erect, flat, leaf-like, attached by rhizoids. 

 (Dictyqte.'E). Dictyotaies. 



35. Nonsexual reproduction by single thallus cells, monospores; trichogyne 



imperfectly developed; no pits between the thallus cells; plants red or 

 purple, mostly filamentous or sometimes stratose. (Moxospor/e) . 

 Bangiales. 



35. Nonsexual reproduction by tetraspores, usually developed in groups of four; 



trichogyne well developed; carpospores developed on filaments after 

 fertilization; cells' of the thallus protoplasmically connected through large 

 pits in the cell walls. (Floride^). 36. 



36. Sporophores ("gonimoblasts" or branches bearing the carpospores) of the 



sporocarp on the sexual plant produced directly from the fertilized 

 oogonium; mostly plants with a filiform frond; fresh water or marine. 

 Nemalionales. 



36. Sporophores produced by auxiliary cells after these conjugate with the 



fertilized oogonia or their branching processes ("oob.lastema"). 37. 



37. Sporophores of the sexual plant produced by nearby auxiliary cells; marine 



plants. 38. 



37. Sporophores produced by remote auxiliary cells after these have conjugated 



with the branched "ooblastema" filaments arising from the fertilized 

 oogonia; fronds filiform, branched, often flattened; mostly marine, but 

 a few fresh water species. Cr5T)tonemiales. 



38. Sporophores produced by nearby auxiliary cells and growing outward in the 



plant body; filiform, foliaceous, or massive plants. Rhodymeniales. 

 38. Sporophores produced by nearby auxiliary cells and branching copiously in 

 the surrounding tissues of the plant body; fronds parenchymarous, erect or 

 spreading, branching, cylindrical, flattened, or leaflike. Gigartinales. 



Phyla, Subphyla, Classes and Subclasses 

 OF Plants. 



A general table of the classification of the plant kingdom on 

 a phyletic basis is given below. At present the writer recognizes 

 50 classes, a class being defined as a group of plants in a sub- 

 kingdom or division whose members show an evident relation- 

 ship. A class may also be defined as the largest, definitely deter- 

 mined, monophyletic group in a subkingdom. A phylum con- 

 sists of one or more classes showing a probable relationship. 

 It might be mentioned that a subkingdom is one of the seven 

 progressive stages into which Hving plants may be divided, each 

 stage being separated from the next higher by a more or less 

 prominent hiatus. 



Phylum I. ScHizoPHYTA. Fission Plants. 



Class L Cyanophyceae. Blue-green Algae. 

 Class 2. Glaucocysteas. Higher Blue-green Algas. 

 Class 3. Schizomycetae. Fission Fungi. 

 Class 4. Myxoschizomycetae. Slime Bacteria. 



