ON PLASMOLYSIS. 161 



these phenomena are of general occurrence in vegetable cells, 

 and more especially whether they are to be observed in those 

 of which the plasmolysed condition has already been described 

 by other writers. 



It being already late in the year, young flower stalks of 

 Cephalaria leucantha (the plant used by de Vries) were 

 not to be had : experiments were, however, made with a 5 per- 

 cent, salt solution upon sections of young leafy stems of this 

 plant, with the result that, though the material was not very 

 favorable, strings of protoplasm, similar to those seen in the 

 prothallus, were found connecting the contracted protoplasm 

 with the cell wall in a large number of cells of the cortical 

 parenchyma. 



Young flower stalks of an allied species (Cephalaria 

 rigida) were also used : sections were cut through the cortical 

 parenchyma and treated with 5 per-cent. salt solution. The 

 same phenomena, as seen in the prothallus, were again repro- 

 duced here in their chief features : the strings of protoplasm, 

 at first not well seen, were quite obvious in the cells after the 

 lapse of one hour (fig. 4). 



The observations of Gardiner on the beet were also verified, 

 it being found that here, on plasmolysis with 10 per-cent. salt 

 solution, strings of protoplasm remain connecting the con- 

 tracted protoplasm with the cell wall. They have frequent 

 nodal swellings, but the strings are not so numerous nor so 

 regular as in the prothallus. 



Sections of the flesh of a ripe apple were also subjected to 

 the same treatment with results similar to those obtained in the 

 beet. 



In leaves of Vallisneria spiralis strings, forming a fine 

 radiating system, are seen some time after plasmolysis with a 

 5 per-cent. salt solution. 



The diaphragms of the intercellular spaces of water plants 

 supply very good material for the study of the phenomena of 

 plasmolysis in parenchymatous cells. Those of the petioles 

 of Limnocharis, sp. Aponogeton distachyon, Alisma 

 Plantago, and Pontederia (Eichornia) coerulea 



VOL. XXIII. NEW SER. L 



