10 



Plant Life and Evolution 



bodies may be sometimes recognized, such as the 

 " microsomes," and there is every reason to 

 look upon the protoplast as an organism, made 

 up of permanent parts or organs, of which only 

 a few, like the chromosomes of the nucleus, and 

 the chromatophores, are readily demonstrated. 



CJ> 



FIG. i 



A Diagram showing the parts of a typical plant cell w, 

 cell wall ; cy, cytoplasm ; n, nucleus ; cr, chromatophores ; v, 

 central vacuole, filled with watery cell-sap. 



B A cell in process of division cs, chromosomes ; C.P., be- 

 ginning of the division-wall ; f, spindle-fibers. 



What the nature of the invisible organs " bio- 

 phores," " pangenes," etc. is, of course, at the pres- 

 ent can only be conjectured, but it is probable that 

 they are of very many kinds and that they always 

 multiply by division as do the nucleus and chro- 

 matophores. Thus there are distributed to the 

 daughter cells after each cell division similar ele- 

 ments which insure a great degree of similarity and 



