CHAPTER 11 



Growing Points and Cell-division 



In some of the simpler forms of plants [e.g. Spirogyra) almost 

 every cell may exhibit growth and division, but, in the vast 

 majority, the cells originate in the first instance by division from 



Fig. 5. — End of a branch of Sphacelaria. The successive segments cut 

 off from the apical cell (a) are lettered in order from the youngest to 

 the oldest (h — e], and show increasing subdivision. 



so-called growing points. These, in the case of a Flowering 

 Plant, are situated at the tips of the stem and root and of their 



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