i8 



Heredity and Environment 



mals and plants the chromosomal vesicles are recognizable even 

 in the resting nucleus (Fig. 8, G), and in every organism the same 

 number of chromosomes, having the same relative shapes and 



FIG. 6. 



FIGS. 6, 7. DIAGRAMS OF SUCCESSIVE STAGES IN THE DIVISION OF A CELL BY 

 MITOSIS. A, Cell with "resting" nucleus and centrosome (c) ; B-E, Early 

 stages of division during which the chromatin takes the form of short 

 thick threads, the chromosomes (C, D, E) while the centrosome gives 



