954: ORIGIN OP THE CALXXi^ 



Linn8eus adopted from Caesalpinus the opi- 

 nion that the Cnii/a proceeded from the bark, 

 hke the leaves, because of its similarity in 

 colour and texture to those organs. He even 

 refined upen the original idea, and supposed 

 this part to proceed from the outer bark, while 

 the more delicate corolla originated m the 

 liber. What is now known of the physiology 

 of the bark, as explained in several of our 

 preceding chapters, renders this hypothesis 

 totally inadmissible. 



The knowledge of the real use of leaves^ 

 see chapter 1 6, may however throw some light 

 upon that of the calyx. Besides protection 

 of the flower from external injuries, which is 

 one evident use of this part, it appears highly 

 probable that it may often contibute to the 

 growth and strength of the stalk which sup- 

 ports it, as the leaves do to that portion of 

 branch below them. The stalk often swells 

 considerably during the growth of the flower, 

 especially just below the calyx, becoming 

 more woody, an alteration frequently neces- 

 sary for the support of the ripening fruit. 

 When the calyx falls very early, as in the 



