98 RELATIONSHIPS OF SYMMETRY 



they are quite young, and this seems to indicate that they have sprung 

 from radial shoots. Here then, as in Vaccinum Myrtillus, an influence is 

 exerted upon the vegetative point of the lateral shoot. 



The examples I have given show that all transitions exist between 

 radial and dorsiventral lateral shoots; in many plants the lateral shoots 



FlG. 53. Phyllantlms mimoaoides. Top of a plant seen obliquely from above. The radial chief axis of the plant 

 is apparently clad \\ith bipinnate leaves ; in reality those are distichously branched leaf-like shoots, the leaves 

 are simple. 



are still radial, dorsiventrality is impressed upon them in the course of 

 their development ; in others the dorsiventrality already exists in the 

 vegetative point and they cannot usually be artificially transformed into 

 the radial form 3 . Relationships of correlation, speaking of these in the 

 widest sense, and the influence of external forces play an important 



1 See the chapter upon Regeneration, p. 43. 



