OF CENTRAL AFRICA. 287 



insertion of the funiculus, its radicle being seated at the 

 opposite extremity of the seed, or to express, in the unim- 

 pregnated ovarium, the infallible indication of this [333 

 position, the direction of the inner membrane and nucleus 

 of the ovulum corresponds with that of its testa. 



But this character, in general very uniform in natural 

 families, and which, equally existing in Cistineae, so 

 well defines the limits of that order, as I have long since 

 remarked,^ would seem to be of less importance in Zygo- 

 phyllese. 



M. Adrien de Jussieu, who, in his memoir already cited," 

 admits its existence in Pagonia, and in both our species of 

 Zygophyllum, considers it as an exception to the general 

 structure of the latter genus, in the definition of which he 

 retains the character of " radicula hilo proxima." I believe, 

 however, that in all the species of Zygophyllum, except 

 Fabago, which, possesses, also, other distinguishing cha- 

 racters, this opposition of the radicle to the external hilum 

 will be found ; for in addition to the two species contained 

 in the herbarium, in both of which it is very manifest, I 

 have observed it in Z. coccineum, and in all the species of 

 South Africa that T have had an opportunity of examining. 

 In some of these species, indeed, it is much less obvious, 

 partly from the greater breadth of the funiculus, and also 

 from its being closely applied, or even slightly adhering to 

 the testa of the seed. But hence it is possible to reconcile 

 the structure of these species with that of Pabago itself, 

 in which the raphe seems to me to be external : and if this 

 be really the case, Fabago differs from those Zygophylla of 

 South Africa alluded to, merely in the more intimate union 

 of the funiciilus with the surface of the testa. Whether 

 this observation might be extended to the other genera of 

 the order, I have not yet attempted to ascertain. 



Balanites ^Egtptiaca, though not belonging to Zygo- 

 phyllese, may be here mentioned. The specimen is from 

 Bornou, but, like all the other plants of that country, has 

 no particular place of growth indicated, nor is there any 



' In Hooker's Flora Scotica, p. 284. 



