20 



BOTANY OF THE LIVING PLANT 

 i. ii. in. 







IV. 



VII. 



V. 











vm. 





Is? •:»-'. ---v.';. •■••-.• -j?' -v- 



i&te-M 



& -•" •- • ■' £ ™ti • j i ill 11 •?■? # ; 'M 



sSS^/^Ka 



Mil-M^Li^iiM 



IX. 



Fig. ii. 



I. -IX. Successive stages, drawn from different individual cells of the same root 

 of Allium cepa by Dr. J. M. Thompson ( x 730). They illustrate the steps in the pro- 

 cess of division of a vegetative cell. Such division accounts for the normal increase 

 in number of cells in the " soma," or plant-body : it is therefore called somatic 

 division. Details of behaviour of the nucleus in division will be given later 

 (Chapter XXXV). 



The division of the cell being constantly as described, it follows that 

 every cell arises from a pre-existent cell. Every nucleus is derived 

 from a pre-existent nucleus by division, and is never produced de novo. 



