ZYG OGONIUM. 175 



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

 not with the branched species. 



When a communication is about 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 endochrome 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 time, 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 thought that the branches which I have so 

 often met with were spurious, and might have been formed 

 in the same manner as they sometimes are in M. genuflexa, 

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

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

 idea was dispelled by observing, that in the specimens in 

 which the branches occurred most abundantly, no union of 

 cells in the regular way 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 have 

 always been found immersed in water; while in others, and 

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

 variably are when found spreading over swampy heaths. 

 Specimens of a beautiful green colour were recently sent me 

 by Mr. Jenner and Mr. Ralfs, and these, for some time, 

 puzzled me exceedingly. 



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

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

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

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

 reptans Carm.) might be referred to it likewise. 



