natural Family of Plants called Composite. 97 



cannot appear very paradoxical to consider them as both of the 

 same nature. 



Jn Dipsacese, however, there is no instance of the outer calyx 

 containing more than one flower, and the evidence afforded by 

 inflorescence on this subject is not altogether satisfactory. 



In Dipsaciis it has been long noticed that expansion begins 

 about the middle of the spilve, and proceeds in opposite direc- 

 tions from the point of commencement: this order is evidently 

 more analogous to that of the compound than of the simple spike; 

 there being several instances of spikes manifestly compound, 

 where the same inversion of the upper part exists. 



But a fact, which I do not find any where observed, respecting 

 the inflorescence of certain species of Scabiosa, particularly sue- 

 cisa and alropurpurea, is not so easily reconcilable with the com- 

 pound spike : in these, and I have reason to think in many other 

 species of the genus, the expansion begins simultaneously at the 

 base and middle of the capitulum, proceeding regularly upwards 

 from both points- Were this the case in all Scabiosae, the com- 

 pound nature of the spike in Dipsaceae, although by no means 

 proved, might be considered not improbable : there are, however, 

 several species of the genus in which the order of expansioQ is 

 altogether that of the simple spike^ 



Connected with the subject of inflorescence, I may remark that 

 priority of development, whether among similar parts in the same 

 flowerorthedifierentflowersof the same spike, is generally accom- 

 panied with greater perfection of these parts or flowers, and ap- 

 parently with greater power of resisting the ordinary causes of 

 abortion or obliteration. 



I have formerly * observed respecting several natural families of 

 plants, in which the stamina are in a determinate number, but a 



* 111 Prodr. Flor. Nov.'Holl. vol. i. and .\p|)endiK to Elindeis's Voyage to Terra Australia. 



•voi. XIX. o number 



