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NATURAL ORDERS.
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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 Samydeæ, but consisting of a mixture of round and linear pellucid dots, distinguish them from all the other families[1] with which there is any probability of their being confounded.

Sir James Smith[2] has lately suggested the near affinity of Aquilaria to Euphorbiaceæ. But I confess it appears to me at least as distinct from that order as from Samydeæ; and I am inclined to think, paradoxical as it may seem, that it would be less difficult to prove its affinity to Thymeleæ than to either of them; a point, however, which, requiring considerable details, I do not mean to attempt in the present essay.


Of EUPHORBIACEÆ there are twenty species in the collection, or one twenty-eighth part of its Phænogamous plants. This is somewhat greater than 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 Euphorbiaceæ in the Congo herbarium are: a new species of the American genus Alchornea; a plant differing from Ægopricon, a genus also belonging to America, chiefly in its capsular fruit; two new species of Bridelia, which has hitherto been observed only in India; and an unpublished genus that I have formerly alluded to,[3] as in some degree explaining the real structure of Euphorbia, and from the consideration of which also it seems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 hermaphrodite flower of that genus, is in reality a compound fasciculus of flowers.[4] From the same species of this unpublished genus a substance resembling caoutchouc is said to be obtained at Sierra Leone.

  1. The only other genus in which I have observed an analogous variety of form in the glands of the leaves, is Myroxylon (to which both Myrospermum and Toluifera belong), in all of whose species this character is very remarkable, the pellucid lines being much longer than in Samydeæ.
  2. Linn. Soc. Transact. 11, p. 230.
  3. Flinders's Voy. 2 p. 557. (Antè), p. 29.)
  4. Linn. Soc. Transact. 12, p. 99.