THE GENERAL SHAPES OF PLANTS. 143 



every sea-coast has abundant examples of stunted trees which, 

 like the one shown in Fig. 199, have been made to deviate 

 from their ordinary equal growth on all sides of a vertical 

 axis, to a growth that is equal only on the opposite sides of a 

 vertical plane directed towards the wind's eye. 



From among vegetal aggregates of the third order, we have 

 now only to add examples of the entirely asymmetrical form 

 which accompanies an entirely irregular distribution of inci- 

 dent forces. Creeping plants furnish such examples. They 

 show, both when climbing up vertical or inclined surfaces and 

 when trailing on the ground, that their branches grow hither 

 and thither as the balance of forces aids or opposes ; and the 

 general outline is without symmetry of any kind, because 

 the environing influences have no kind of regularity in their 

 arrangement. 



220. Along with some unfamiliar facts, I have here set 

 down facts which are so familiar as to seem scarcely worth 

 noting. It is because these facts have become meaningless 

 to perceptions deadened by infinite repetitions of them, that 

 it is needful here to point out their meanings. Not alone for 

 its intrinsic importance has the unlikeness between the 

 attached ends and the free ends been traced among plants of 

 all degrees of integration. Nor is it simply because of the 

 significance they have in themselves, that instances have 

 been given of those varieties of symmetry and asymmetry 

 which the free ends of plants equally display: be they plants 

 of the first, second, third, or any higher order. Neither has* 

 the only other purpose been that of showing how, in the radial 

 symmetry of some vegetal aggregates and the single bilateral 

 symmetry of others, there are traceable the same ultimate 

 principles as in the spherical symmetry and triple bilateral 

 symmetry of certain minute plants first described. But the 

 main object has been to present, under their simplest aspects, 

 those general laws of morphological differentiation which are 

 fulfilled by the component parts of each plant. 



