26 VEGETABLE ORGANOGRAPHY. 



§ 2.— Of Corymbs. 

 The inverse to all that we have yet observed takes 

 place in the Corymb {corymbus). This term has 

 hitherto, in all the writings of botanists, been used in a 

 vague sense, and solely founded upon appearance. I 

 propose to limit it to a very distinct case, which deserves 

 a special name, viz. the case of inflorescences where the 

 central axis follows the laws of terminal inflorescence, 

 and the lateral branches, that of indefinite ; almost all 

 the Composite are examples of this system, and the 

 name of Corymbiferae has for this reason been given to 

 several of them. If we follow the development of Tolpis, 

 or of most of the Composite, we see that the central 

 axis terminates in a capitulum, and that the lateral 

 branches are developed in a centrifugal order ; those 

 which are nearest the central capitulum (which may 

 be here provisionally considered as a flower) expand 

 first ; but all these successive capitula, which, compared 

 together, follow the centrifugal evolution, are indivi- 

 dually subject to the laws of the centripetal, in each of 

 them the expansion of the flowers proceeding from the 

 circumference to the centre. When the corymbs are 

 very near together, as, for example, in Cardopatum, the 

 expansion appears perfectly irregular, because the 

 flowers of each capitulum, or the capitula of the whole 

 corymb, follow two different systems of evolution. 

 When the partial capitula are reduced to a single flower, 

 the whole evolution is centrifugal, in which this head, 

 composed of capitula, differs much from true capitula ; 

 this happens in Echinops. When the capitula are soli- 

 tary, or, in other terms, when the lateral branches are 

 not developed, the single capitulum flowers after the 

 system of indefinite inflorescence alone, and then the 

 head of a monocephalous compound flower does not 

 differ from that of other flowers in capitula. 



