Ko. 640] BODY SIZE AND ORGAN SIZE 395 



plant size increases (Fig. 2), showing no sign of the 

 flattening characteristic of the mature plants. 



What reason may we assign in the case of the mature 

 plants for this radical difference between large individ- 

 uals and small ones? And why, in immature plants, 

 should no such difference exist! The suggestion at once 

 comes to mind that there may really be no relation be- 

 tween body size and organ size in any case, but that 

 organ size may be determined, instead, by the size of the 

 particular axial growing point from which the organ has 



TABLE V 



BELOW THE Vertical Line in Fig. 1) ; 



ABOVE THE VERTICAL LiNE IN FiG. 1). 



devek)])ed. It is a matter of common observation that in 

 most lierbaceous phmts the diameter of the newly formed 

 stem internodes (and therefore presumably the diameter 

 of the terminal growing point which dves rise to the 

 primary tissues of the stem) i> cdniparativoly small in 

 the seedling, but increases slowly as the plant grows 

 larger until a presumably optiiinmi diameter is attained 

 wliicli i>; rarely exceeded except in the case of very rank 

 and luxuriant shoots. Furtlier ixrowtli of the plant as 

 a whole results in an increase in the length and number 



Stern dianictcr is of course not uniform, many lateral 



