1 8 Synopsis of the Bacteria and Yeast Fungi. 



Micr. Sri., xiii. 408, pi. 22-3 ; xv. 206 ; and xvi. 



27, pl- 3)- 



Clathrocystis roseo-persicina, Cohn. 



\Monostroma rosea, Currey.] 



\Beggiatoa roseo-persirina, Zopf (pro parte).~\ 

 Cells round, oval, or, by mutual pressure, polygonal, 

 varying from rose to purple-red, reaching 2^ fj. in diameter. 

 They form at first small solid families, in which the single 

 cells are bound together by gelatine, while the whole family 

 is surrounded in addition by a gelatinous envelope. Later, 

 the families become larger, globular or ovoid, and finally 

 irregular bodies, which are hollow and filled with a watery 

 fluid, and reach a diameter of 660 p. (= f mm. or -^ s inch). 

 In these the cells form a simple peripheral layer. These 

 vesicles are often torn or perforated ; in the end they pre- 

 sent an elegant network, which finally breaks up into 

 irregular rags and tatters. (Fig. 9.) 



In marshes, floating on the surface or amongst Algae 

 and Lemna ; often also in a room, in water in which Algae, 

 etc, are decaying. 



The single hitherto known species of this genus is distinguished by 

 its red colouring matter, which is essentially different from that of 

 Micrococcus prodigiosus, and is designated "bacterio-purpurin." It is 

 insoluble in water, alcohol, etc., is changed by hot alcohol into a brown 

 substance, and is moreover characterised by its optical behaviour. For 

 in the spectroscope it shows strong absorption in the yellow, less in the 

 green and blue, as well as a darkening in the more refrangible half of 

 the spectrum.* Each individual cell is surrounded by a dense, almost 

 cartilaginous membrane ; its contents are at first homogeneous, but as 

 it grows older one or more dark granules t can be observed in it, which 

 are nothing else but pure eliminated sulphur. 



[By the kindness of Mr. J. Levick, then President of the Birmingham 



* For the spectrum, see Quart. Jour. Micr. Set., xiii. 425. TR. 

 t The granules are the "loculi" of Lankester, and the "spores" 

 of other authors. TR. 



