126 



RELATIONSHIPS OF SYMMETRY 



I'. LEAFLETS OF UNEQUAL SIZE. 



Mimosa sensitiva supplies an example of the different develop- 

 ment of the leaflets of one and the same leaf 1 . This feature appears 



FIG. 77. Lathyrus Apliaca. Transverse section through th >hoot-apex. The large 

 stipules alone protect the bud. 



FIG. 78. Vicia Cracca. Transverse section through a shoot-apex. 1-6 pinnate 

 leaves, the stipules s/\-sl t ; of which fill up the space both above and below between the 

 leaves and so protect the bud. See also explanation ol Fig. 83. 



FIG. 76. Lathyrus 

 Aphaca. Seedling. The 

 stipules of the two lower 

 leaves in which the leaf- 

 lamina is formed are 

 asymmetric, but those 

 of the upper leaves in 

 which the leaf-lamina is 

 arrested are symmetric. 



FIG. 79. Vicia Cracca. Transverse section through a chief axis H. In the axil 

 of the leaf to the left stands the inflorescence J, and below it is the accessory shoot S, 

 which has also already produced axillary inflorescences indicated by shading in the 

 figure. The plane of symmetry of the shoot 6" is almost parallel with that of the chief 

 shoot. The inflorescences in both are displaced towards the illuminated side. 



1 We leave out of account the smaller differences in size which frequently occur and are due to 

 the later-formed leaflets not reaching the dimensions of the earlier ones. 



