118 BOTANY OF CONGO. 



siderably until the extrication is complete, when expansion 

 takes place. 



It is singular tliat this mode of cohesion between the 

 ovarium and calyx in certain genera of Melastomacese, and 

 the equally remarkable aestivation of antherae accompanying 

 it, should have been universally overlooked, especially in 

 the late monograph of M. Bonpland ; as both the struc- 

 ture and economy certainly exist in some, and probably in 

 the greater part, of the plants which that author has 

 figured and clescribed as belonging to Rhexia. 



On the limits, structure, and generic division of Melasto- 

 macese, I may remark — 



1st. That Memecylon, as M. du Petit Thouars has 

 already suggested,^ and Petaloma of Swartz^ both belong 

 to this order, and connect it with Mijrtacece, from which 

 they are to be distinguished only by the absence of the 

 pellucid glands of the leaves and other parts, existing in 

 all the genera really belonging to that extensive family. 



2ndly. There are very few Melastomacese in which the 

 ovarium does not in some degree cohere wdth the tube of 

 the calyx ; Meriana, properly so called, being, perhaps, 

 the only exception. 



And in the greater number of instances where, though 

 the ovarium is coherent, the fruit is distinct, it becomes so 

 from the laceration of the connecting processes already 

 described. 



3rdly. That the generic divisions of the whole order 

 remain to be established. On examination, I believe, it 

 will be found that the original species of the Linnean 

 genera, Melastoma and Bhexia, possess generic characters 

 sufficiently distinguishing them from the greater part of 

 the plants that have been since added to them by various 

 authors. In consequence of these additions, however, 

 their botanical history has been so far neglected, that pro- 

 bably no genuine species of Melastoma, and certainly none 

 of Rhexia, has yet been published in M. Bonpland's splen- 

 did and valuable monographs of these two genera. 



^ Melanges de Bof unique ; Observ. address, a M. Lamarck, p. 57. 

 2 Flor, hid. Occid. 2, p. 831, tab. 14. 



