Marks , employed for classifying the Schizomycetes . 125 
attempted. When we reflect that Winter, even so lately as 
1881, only described sixty-nine species, we obtain some idea 
of the extraordinary activity which has been displayed within 
the last ten years. I append Trevisan and De-Toni’s scheme 
in tabular form. 
TABLE VII. — De-Toni and Trevisan , 1889. 
I. Trichogenae. 
Presenting three vegetative stages — filaments, rodlets and cocci. 
The filament is the typical individual, sheathed or not, and is usually 
differentiated into apex and base, the plants being fixed by the latter 
and radiating from a central point. Some have no distinction between 
base and apex. Rodlets and cocci enclosed in the filaments. 
A. Spores (arthrospores) developed in special sections of fila- 
ments (pseudo-sporangia) (Crenotrieheae). 
Crenothrix . Filaments simple, sheathed. 
B. Spores (arthrospores) in the normal filaments. 
(a) Filaments falsely branched (Cladotricheae). 
(i) Sheathed. 
Sphaerotilus. Filaments uniform in diameter from 
base to apex. Arthrospores very numerous. 
Divisions in three planes. 
Cladolhrix. Filaments widening upwards. Arthro- 
spores developed in pairs in individual rodlets. 
(ii) Filaments devoid of sheaths. 
Nocar dia. Arthrospores produced by the trans- 
formation of cocci. 
(/ 3 ) Filaments simple (Kurthieae). 
(i) Arthrospores 4-5 in individual rodlets. 
Detoniella. 
(ii) Arthrospores consisting of transformed cocci. 
Rasmussenia. Filaments fixed below. 
Kurthia. Filaments equal throughout and free. 
C. Spores absent, or unknown. Filaments simple (Leptotri- 
cheae). 
(a) Filaments sheathed and differentiated into base and 
broader apex, fixed. 
Leptotrichia . Reproduced by rod-shaped gonidia. 
