388 The Ohio Naturalist. [Vol. VI, No. 1, 



• 



The first and second subkingdoms are Thallophyta; the 

 third, fourth, and fifth are Archegoniata ; and the sixth and 

 seventh are Spemiatophyta. 



It is often convenient to separate the chlorophyll-bearing 

 Thallophvtes from those without chlorophyll. Thallophytes with 

 chlorophvll are Algae. Thallophytes without chlorophyll are 

 Fungi. Protophvtes with chlorophyll tire Protophyceae. Pro- 

 tophvtes without chlorophyll are Protomycetes. Nematophytes 

 with chlorophvll are Gamophyceae. Nematophytes without 

 chlorophyll are Eumycetes. 



The seven subkingdoms may be characterized as follows: 



I. Protophyta. Protophytes. 3,000 known living species 



Plants without sexuality, representinj^ direct descendants from prim- 

 itive nonsexual organisms; typically unicellular, the cells free, in colonies, 

 in plasmodial masses, or in simple or branched filaments which are free or 

 fixed and in the more highly specialized forms with definite base and 

 apex; nonmotile, or having locomotion either by means of fiagella, cilia, 

 or pscudopodia, or by the general contraction of the cell; holophytic or 

 phagophytic; with chlorophyll or without; reproduction by simple fission, 

 by zoospores, or by walled or encysted spores l:)y means of which the 

 plant survives dessication. 



II. Nematophyta. Nematophytes. 57,000 known living 



species. 



Plants which have developed sexuality, some type of conjugation 

 being present except in some groups which are supposed to have under- 

 gone degeneration from sexual- ancestors; the more highly developed 

 forms frequently Avith a primitive alternation of generations: plant body 

 usually filamentous, either simple or branched, free or fixed, but in some 

 groups unicellular, coenobioid, or a complex solid aggregate; chlorophyll 

 present or absent, the great majority of species without chlorophyll living 

 in aerial conditions as parasites or saprophytes, those with chlorophyll 

 usually being hydrophytes. 



III. Bryophyta. Bryophytes. About 14,000 known living 



species. 



Plants, visually of small size, in which there is a typical sporophyte 

 l)ut this never having an independent existence, being supported on the 

 gametophytc in a parasitic condition during its entire life; without true 

 vascular tissue, true roots, or leaves, but sometimes with true stomata; 

 always homosporous. Gametophyte comparatively large, consisting of a 

 thalloid frond or a stem -like, scaly frond, usually preceded by a fila- 

 mentous jirocmbryo, the protonema, which develops from the spore. 



IV. Pteridopiiyta, Homosporae. Homosporous Pterido- 

 phytes. 2,800 known living species. 



Plants in wliich the herbaceous or tree-like sporophyte, after the 

 juvenile stage, has an independent existence with true fibro-vascular tis- 

 sue, roots, and leaves, and with a terminal growing point; homosporous 

 and either eusi)orangiate or leptosporangiale. Gametophyte usually 

 rather large, normally hermaphrodite altliougli ol'tcn unisexual; thalloid 

 and green but sometimes tuberous and subterranean and witliout 

 chlorophyll 



