Schizomycetes. 3 



hitherto been described as Algae, but which, on account of 

 their want of chlorophyll^ and their decomposing power, must 

 be reckoned among the Fungi. 



The Fungi here treated of are the smallest with which 

 we are acquainted. The form of the cells is various — round, 

 ovate, elliptic/ cylindrical, etc. They live isolated, singly or 

 in larger or smaller swarms, or in many cases united in pairs, 

 or many together in threads or groups. Many forms are 

 always motionless ; others, on the contrary, show a more or 

 less active spontaneous movement, which is frequently 

 effected by flagella. In this case the cells swim about 

 swiftly, rotating round their longitudinal axis. In other 

 cases the movement is an oscillating one or the threads 

 alternately bend and straighten themselves, etc. 



But even the motile forms for the most part possess 

 certain stages in which they are motionless. In this case, 

 usually, countless aggregated cells excrete a gelatinous or 

 slimy mass, which either presents a sharply bounded, 

 variously shaped contour — round, sac-like, ragged, or even 

 branching — or else is without definite outline. Such a 

 gelatinous colony is designated a zooglcea ; it is a resting- 

 stage, which often precedes the formation of spores, and 

 often also occurs in typically motionless forms. 



The formation of spores is known in many Schizomycetes ; 

 it has been most accurately observed in Bacillus subtilis, in 

 which I will briefly describe it. The cells of the genus 

 Bacillus are short cylindrical rods, which increase by repeated 

 transverse division, and have a flagellum at each end, by the 

 active vibration of which the rod is moved. In spore-form- 

 ation the greater part of the contents collects at one point 

 of the rod, which often projects as a swelUng, and is sharply 

 marked off from the other empty part of the cell. After- 

 wards this strongly refringent, dark-looking body (the spore) 



