32 Elementary Biology. 



It is found that all cells undergo certain changes during 

 their existence changes concomitant with the phenomena 

 known popularly as growth, reproduction, decay, and death 



FIG. 4. CELLS FROM THE ROOT OF Frltillaria imperialis ( x 550). (Sachs.) 



c' v *.'' A 



h 



A, very young cells from near apex ; B, from 2 mm. above the apex ; c, from about 

 8 mm. above the apex, /i, cell-wall ; p, protoplasm ; k, nucleus ; k k, nucleoli ; 

 s, vacuoles and cell-sap cavity. 



changes in which the protoplasm and its modifications 

 play different parts, perform different duties or functions. 



The performance of any function, i.e. the doing of any 

 work, as already fully explained (Chapter I., section ii), 



