8 



ON THE NATURAL SYSTEM. 



The families included in the Apetalous and Monopetalous Divisions will be found true to their appellations, the former being all apetalous and the latter all monopetalous, but in the 

 Polypetalous Division are included some of the apetalous families because their nearest affinities are with one or more of the polypetalous families, and so decidedly so, that they would be out of 

 place in the Apetalous Division, as for instance Tetragoniacece and Callitrichacece. This appeared unavoidable consistently with the principal object in the present arrangement, which is to 

 place each family with its nearest allies, and then to show how far characters structural and physiological can be made, consistently with the principles of scientific botany, to support such an 

 arrangement. 



The expression "next the placenta," made use of in the Tables in reference to the position of the raphe, is equivalent to "raphe ventral," an expression referring to the same 

 character, both in erect and pendulous ovules, in the ' Genera Plantarum' of Bentham and Hooker ; — " next the placenta" will perhaps be more readily understood by those who have not given 

 especial attention to the subject. 



