444 APPENDIX. No. V. 



should then propose to apply the name of Aquilabin* in preference to 

 Chailletea?. 



The genus Aquilaria itself has been referred by Ventenat to Saviydece. 

 From tills order, however, it is sufficiently distinct, not only in the structure of 

 its ovarium and seeds, but in its leaves being altogether destitute of glands, 

 which are not only numerous in Samydeae, but consisting of a mixture of round 

 and linear pellucid dots, distinguish them from all the other families* with 

 which there is any probability of their being confounded. 



Sir James Smith -f has lately suggested the near affinity of Aquilaria to 

 Euphorbiaceae. But I confess it appears to me at least as distinct from that 

 order as from Samydeae : and I am inclined to think, paradoxical as it may 

 seem, that it would be less difficult to prove its affinity to Thymeleae than to 

 either of them ; a point however which, requiring considerable details, I do 

 not mean to attempt in the present essay. 



Of EUPHORBIACEiE there are twenty species in the collection, or one 

 twenty-eighth part of its Phaenogamous plants. This is somewhat greater tlian 

 the intratropical proportion of the order as stated by Baron Humboldt, but 

 rather smaller than that of India or of the northern parts of New Holland. 



The most remarkable plants of Euphorbiaceae in the Congo herbarium are ; 

 a new species of the American genus Alchor7iea ; a plant differing from 

 JEgoprkon, a genus also belonging to America, chiefly in its capsular fruit ; 

 two new species of Br'idel'm, which has hitherto been observed only in India ; 

 and an unpubhshed genus that I have formerly alluded to,| as in some degree 

 explaining the real structure of Euphorbia, and from the consideration of 

 which also it seems probable that what was formerly described as the herma- 

 phrodite flower of that genus, is in reality a compound fasciculus of flowers.§ 

 From the same species of this unpublished genus a substance resembling 

 Caoutchouc is said to be obtained at Sierra Leone. 



According to IMr. Lockhart a frutescent species of Euphorbia, about eight 



* Tlie only other genus in which I have observed an analogous variety of form in the 

 glands of the leaves, is Myroxylon, (to which both Mt/rospermum and Toluifera belong,) 

 in all of whose species this character is very reraarkabie, the pellucid lines being much 

 longer than in Samydeas. + Linn. Soc. Transact. \\,p. 230. 



t FUHdersi V03. 9, p. 557. \ Linn, Sac. Transact. 12, p. 99. 



