22 VEGETABLE ORGANOGRAPHY. 



Section IV. 



Of Mixed Inflorescences, or those which partake of the 



two preceding. 



Inflorescences may be mixed after two different sys- 

 tems; viz. either, 1st, because the central axis proceeds 

 in the manner of indefinite inflorescences, and the lateral 

 branches follow the progress of terminal ones ; or 2d, 

 because the central axis proceeds in the manner of ter- 

 minal inflorescences, and the lateral branches follow 

 the progress of indefinite ones. 



To the first of these divisions belong the true Thyrses ; 

 to the second, the true Corymbs. Let us examine the 

 modifications of these two inflorescences, and their par- 

 ticular affinities with the two preceding classes. 



§ 1.— Of Thyrses. 



If I examine one of the Labiata?, I see that the stem 

 or branch is prolonged indefinitely by its extremity, and 

 that the pairs of leaves may be there developed succes- 

 sively, one after the other, without any other natural 

 termination than that of the vegetation ; all the inflo- 

 rescences proceed from the axils of the leaves, and each 

 is a di- or trichotomous cyme. Thus, the whole inflores- 

 cence of the Labiatae is a Thyrse, interrupted by the 

 distance of the internodes and the great development of 

 the leaves from the axils of which the cymes are deve- 

 loped. When these cymes are very lax, this disposition 

 is very evident ; when they are close and compact, so 

 as to form axillary fascicles, the union then of two 



