526 THE NATURAL HISTORY OF 



Zellsaftes,' in Nitella flexilis ; by Goppert and Cohn, 

 Botanische Zeitung, 1849, No. 37 40.) 



There are, however, phases of development in which 

 the colourless or almost aqueous cell-contents can be dis- 

 tinctly denned from the denser, coloured, gelatinous, 

 peripheral substance. Whilst, therefore, in most cases, 

 the still form, according to Kutzing's terminology, would 

 have to be regarded as hologonimic full-cells, in which 

 the solid contents completely fill the cell, so, when the 

 primordial sac and cell-juice are separated, they would 

 necessarily come under the denomination of ccelogonimic, 

 hollow cells. 



The contents vary very much in consistence, colour, 

 and solid constituents. 



The red and green portions of the contents appear to 

 be of equal physiological importance. 



The green colour is removed by ether, on the evaporation 

 of which solvent there remain green, afterwards colour- 

 less drops. Dilute sulphuric acid at first renders the 

 colour paler ; but its prolonged action produces a bright 

 verdigris hue, which gradually becomes more and more 

 intense, and often almost a blue green. Hydrochloric 

 acid has a similar effect ; a tinge of brown is produced 

 by nitric acid. Carbonate of potass scarcely affects the 

 green colour; it is gradually but totally destroyed by 

 caustic potass, the contents at the same time swelling 

 and becoming transparent. 



The red colour is also to some extent soluble in ether, 

 but is less affected, or scarcely at all by any of the other re- 

 agents above enumerated. It diners, therefore, from the 

 erythrophyll or the acidified anthocyanine of chemists, as 

 well as from the colouring matter of litmus and phycoery- 

 thrin, which, according to Kiitzing, is peculiar to the Flo- 

 rideaB. In its chemical relations it seems most nearly allied 

 to the phycohaematin of Bytiphlaa tinctoria, but the latter 

 is insoluble in ether. It also seems to be related to the 

 orange coloured oil, which, according to Niigeli, is formed, 

 under morbid conditions, in many unicellular Algae. 



