22 
CONTRIBUTIONS TO BOTANY. 
of the latter order to be caljT: and corolla, both of which are 
often most distinctly developed, as in Choretrum, Leptomeria, 
Leptonium and Mida, as also in Quinchamalium, Arjoona and 
Mijoschilos, it is clear that its relationship towards the Olacacea 
is infinitely stronger than with the Thymeleacea, ProteacecB and 
Lauracea, to which, in fact, they claim but a most distant affinity. 
This consideration did not escape the penetration of ]\Ir. Brown, 
who more than forty years ago, and some time before the esta- 
bhshment of the family of the Olacacea, suggested* that the floral 
envelope called perianthium in the Santalaceee may be looked 
upon as analogous to the same organ called corolla in Olax, and 
the calycular appendages may be viewed as a distinct calyx, 
alike in both instances ; and hence, with equal reason in one 
case as in the other, we may consider the floral envelopes to be 
dichlamydeous rather than monochlamydeous ; or we may 
imagine, that at a very early period in the development of the 
bud, the cal)"x and corolla have become connate, and hence 
grown into one common envelope, — an hypothesis rendered very 
probable from the constant thickness of its substance, and its 
divisibility into two distinct laminae. I was led to a similar 
conclusion many years since by the examination of the Chilean 
genera Quinchamalium, Myoschilos and Arjoona, which have all a 
very distinct calyx, while the more conspicuous envelope, hitherto 
called perigonium, is decidedly petaloid in texture. Under this 
point of view, a close relationship will be found to exist between 
the OlacacecE, Santalacea and Styracece, to which perhaps may 
also be added the Mxjrsinacece. (but not the Primulacea) , 
and it would then remain to be decided, in what part of the 
system such an alliance ought to And its plaee. I will not at 
present stop to ofFer proof of the alliance of the Santalacea with 
the orders above-mentioned, as I shall shortly have to revert to 
that consideration, but assume the fact for the present as one 
that admits of little doubt, and proceed to speak of the affinities 
of the Olacacect in other quarters, taking this family within the 
limits it has hitherto embraced. 
I have alluded to the relationship of the Olacacea with the 
StyracecE, but in so doing it is requisite here to state, that I 
consider the SymplocacecE as ordinally distinct from the StyracecE, 
as will be made apparent when I describe two new genera ap- 
pertaining to the former family. Don first suggested this 
separation, but he does not appear to have been aware of all the 
facts that prove their want of identity. In the SymplocacecE we 
find a calyx of five imbricate sepals, a corolla uuth veiy imbricated 
aestivation, numerous stamens, placed in many series upon the 
corolla, having ovate 2-lobed anthers, without intervening con- 
* Prodr. 352. 
