ZYGOGONIUM. 175 



to make it apparent that its proper station is with these, and 

 not with the branched species. 



When a communication is abont to be set up between two 

 cells in the same filament, the opposed extremities of those 

 cells are first seen to become slightly inflated, to point some- 

 what and then burst, effusing their contents sometimes into 

 a space which is formed gradually between the two cells, 

 but at others the endochromc of one cell passes directly 

 into the cavity of the other. 



All the cells in a filament do not usually communicate 

 with each other at the same timis, but at distant intervals ; 

 and around those cells between which a communication is 

 about to become established, the investing membrane is ob- 

 served to be thickened considerably, pointing out to the 

 observer those cells which either have, or are about to take 

 on, the characters of reproduction. 



At one time I tliought that the branches which I have so 

 often met with Averc spurious, and might have been formed 

 in the same manner as they sometimes are in il7. genujlcxay 

 &c., viz. by the union of the extremities of certain filaments 

 at right angles Avith the cells of other filaments ; but this 

 idea was dispelled by observing, that in the specimens in 

 wdiich the branches occurred most abundantly, no union of 

 cells in the regular Avay was to be met with. 



The colour no less than the condition of the endochrome 

 varies considerably in this species. In some specimens the 

 filaments are of a bright green, in which case they ha^e 

 always been found immersed in Avater ; Avhile in others, and 

 more frequently, they are purple ; of which colour they in- 

 variably are Avhcn found spreading over swampy heatlis. 

 Specimens of a beautiful green colour Avere recently sent me 

 by ]\Ir. Jenner and ]\Ir. Ealfs, and these, for some time, 

 puzzled me exceedingly. 



I have no liesitation in referring to this species the C. pur- 

 purascens of Carmichael, and C. alpina Bory Avhich is but an 

 aquatic condition of the plant, and strongly suspect that Conf. 

 turtuosa Dillw. (the Zygnema littoreum Lyngb., and C. per-' 

 rcptans Carm.) might be referred to it likcAA'ise. 



