436 APPEXDIX. Xo. V. 



this cohesion is partial, and such as I have now described, being lodged in the 

 tubular interstices ; their points extending to the base of the ovarium. From 

 these sheaths, to which they are exactly adapted, the antherae seem to be dis- 

 engaged in consequence of the unequal growth of the different parts of the 

 filament ; the inflected portion ceasing to increase in length at an early period, 

 while that below the curvature continues to elongate considerably until the 

 extrication is complete, when expansion takes place. 



It is singular that this mode of cohesion between the ovarium and calyx in 

 certain genera of Melastomaceae, and the equally remarkable aestivation of 

 antherae accompanying it, should have been universally overlooked, especially in 

 the late monograph of IM. Bonpland ; as both the structure and economy cer- 

 tainly exist in some, and probably in the greater part, of the plants which that 

 author has figured and described as beloneina; to Rhexia. 



On the limits, structure, and generic division of Melastomaceae, I may 

 remark, 



1st. That Memecylon, as M. du Petit Thouars has already suggested,* and 

 Petalonia of Swartz-(- both belong to this order, and connect it with Myriacece, 

 from which tliey are to be distinguished only by the absence of the pellucid 

 glands of the leaves and of other parts, existing in all the genera really 

 belonging to that extensive family. 



2dly. Tliere are very few Melastomaceae in which the ovarium does not in 

 some degree coliere with the tube of the calyx ; Meriana, properlv 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 connect- 

 ing processes already described. 



3dly. That the generic divisions of the whole order remain to be established. 

 On examination, I believe, it ^nll be found that the original species of the 

 Linnean genera, Melastoma and Rhexia, possess generic characters sufliciently 

 distinguishing them from the greater part of the plants that have been since 

 added to them by various authors. In consequence of these additions, how- 

 ever, their botanical history has been so far neglected, that probablv no aenuine 

 species of Melastoma, and certainly none of Rliexia, has yet been published in 

 M. Bonpland's splendid and valuable monographs of these two genera. 



* MHanges de Botanique ; Ol/serv. address, a M. Lamarck, p. 57, 

 + JFior. Ind. Occid. 2, p. 831 , tub. 14. 



