HAIRY FRUITS 



261 



FIG. 65 

 ACHENE AND PAPPUS 



VALERIAN A, the Valerian, 

 which grows on the mountains 

 of South India, and belongs 

 to quite another family. The 

 hairs are in these cases con- 

 sidered to represent the 

 sepals, which are otherwise 

 undeveloped and barely visible 

 in the flower. 



3. All these outgrowths, 

 wings and hairs, on the fruit 

 or on the seed, have the same 

 effect, to make the seed 

 buoyant and so enable the 

 wind to carry it some distance 

 away from the parent plant. 

 And we see that structures 



having for their object the same purpose, may arise 

 in several different ways : as a single enlargement 

 (wing) or as many small outgrowths (hairs) of the 

 seed or the fruit, or as enlargements of the styles or 

 the sepals. The study of plants shows up many 

 instances of the same kind, and of some we have 

 already become acquainted in chapters v and xv. 

 As was explained there, we may regard any organ or 

 structure from the point of view of its function (that 

 is of its use to the plant), or from the point of view 

 of its origin and its connexion with other organs. The 

 study of the former is its physiology, of the latter its 

 homology. The function of all these wings and hairs 

 on the fruits and seeds is the same, their homology 

 is different. 



