Classification of the Schizomycetes. 75 



is mostly only one spore in each cell. The zooglcea forms 

 are produced by aggregation, combined with the same 

 tendency of the cell-walls to gelatinise which is found in 

 many of the lower Algae. 



As the result of his observations, Zopf proposes the 

 following classification : — 



I. CoccfACE/E. Possessing only the (micro-)coccus form, and the 



thread fcsrm which arises from the juxtaposition of the cocci in 

 aline ... ... ,.. ... ... Leuconostoc 



II. BacteriacE/«. Possessing four forms, cocci, bacteria (short 



rods), bacilli (long rods), and leptothrix threads. The last 

 show no distinction between base and apex. No spirals 



Bacterium, Clostridium 



m. LeptotrichE/E. Possessing five forms, cocci, bacteria, ba- 

 cilli, leptothrix (which last shows a distinction between base 

 and apex), and spiral forms 



Leptothrix, Beggiatoa, Crenothrix, Phragmidiothrix 



IV. Clad0TRICHE/«. Possessing coccus, rod, thread, and spiral 

 forms. Threads provided with false branching (pseudo-dicho- 

 tomy) ,.. ... ... ... ... Cladothrix 



There is one more development of opinion with respect 

 to the Schizomycetes of which mention must now be made. 

 The belief is gaining ground that, among the lowest forms 

 of vegetal life, no such sharp distinction as hitherto can 

 be drawn between those which contain chlorophyll (the 

 algal series) and those which do not (the fungal series). 

 This view, which is embodied in the classification adopted 

 by Sachs in the later editions of his text-book of Botany, 

 is approved by Cohn (see Quart. Jour. Micr. Set., 1876, 

 pp. 27s, 276), and is now supported by Zopf himself 

 According to the latter, such Algae as Glaucothrix and 

 Gliothrix, etc., show Chroococcus-like stages of develop- 

 ment which answer to the Micrococcus stage among the 

 Schizomycetes. The tendency of both to aggregate in 

 gelatinous colonies has been already adverted to. More-^ 



