OF CENTRAL AFRICA. 291 



fore, exceptions to all the assumed characters of Mimosege 

 are found, and there is some approach in both genera to 

 the habit of Cgesalpine^. It is still possible, however, to 

 distinguish, and it will certainly be expedient to preserve, 

 these two tribes or orders. Abandoning divisions strictly- 

 natural, and so extensive as the tribes in question, merely 

 because we may not be able to define them with precision, 

 while it would imply, what is far fi-om being the case, that 

 our analysis of their structure is complete, woxild, at the 

 same time, be fatal to many natural families of plants at 

 present admitted, and among others to the universally re- 

 ceived class to which these tribes belong. No clear cha- 

 racter, at least, is pointed out in the late elaborate work of M. 

 De CandoUe,^ by which Leguminosge may be distinguished 

 from Terebintacese and Rosacese, the orders supposed to be 

 most nearly related to it. It is possible, however, that such 

 characters, though hitherto overlooked, may really exist ; 

 and I shall endeavour to show that Leguminosse, indepen- 

 dent of the important but minute diiFerences in the original 

 structure and development of its ovulum, may still be dis- 

 tinguished at least from Eosacese. 



In the character of Polygalese, which I published in 1814,^ 

 I marked the relation of the parts of the floral envelopes to 

 the axis of the spike, or to the subtending bractea. I in- 

 troduced this circumstance chiefly to contrast Polygalese 

 with Leguminosse, and to prove, as I conceived, that Secu- 

 ridaca, which had generally been referred to the latter 

 family, really belonged to the former. 



M. De Jussieu, who soon after published a character of 

 Polygalese, entirely omitted this consideration, and con- 

 tinued to refer Securidaca to Leguminosse. M. De Can- 

 doUe, however, in the first volume of his ' Prodromus,' has 

 adopted both the character and limits of Polygalese, which [336 

 I had proposed, though apparently not altogether satisfied 

 with the description he himself has given of the divisions of 

 the calyx and corolla. 



The disposition of the parts of the floral envelopes, with 



■ Memoires sur la Famille des Legumineuses. 



2 Minders' s Voy. to Terra Austr. %,p. 543. {Ante, pp. 13, 14.) 



