32 



PHYSIOLOGY 



vacuole are regenerated, but all non- nucleated fragments quickly 

 perish (Fig. 9). M 



Many similar observations have shown that the non-nucleated 

 cytoplasm, though it may survive for some time and perform normal 

 movements in response to stimuli, such as those of ingestion of food 



A 



ft 



C 



D 



FIG. 10. Formation of membranes by protoplasmic fragments of plasmolysed cells. 



(WILSON after TOWNSEND.) 



A. Plasmolysed cell, leaf-hair of Cucurbita, showing protoplasmic balls 

 connected by strands. B. Calyx-hair of Gaillardia ; nucleated fragment 

 with membrane, non-nucleated one naked. <7. Root-hair of Marchantia ; all 

 the fragments, connected by protoplasmic strands, have formed membranes. 

 D. Leaf -hair of Cucurbita ; non-nucleated fragment, with membrane, connected 

 with nucleated fragment of adjoining cell. 



particles, loses entirely the power of digestion, secretion, and growth. 

 In animals possessing a shell, a small secretion of the lime salts may 

 occur on the surface, but this process rapidly comes to an end as the 

 store of material in the cytoplasm is exhausted. In vegetable cells 

 it is possible to break up the protoplasm by means of plasmolysis 

 into nucleated and non-nucleated parts. The nucleated part quickly 

 forms a new cell wall. The non-nucleated part is unable to effect this 

 formation, and soon dies unless it is in connection with an adjacent 



