174 Mr. J. Miers on the Affinities of the Olacaceae. 



that family, and that its affinity with the Olacacece is in reaHty 

 very distant. This very different structure of the ovarium did 

 not escape the penetration of Mr. Bentham, but as he had not 

 observed the constant, essential, and dissimilar points of floral 

 structure, as above described, he states in the memoir before 

 cited, that he did not consider the single fact noticed by him to 

 be a sufficient reason for separating the Icacinea from the Ola- 

 cacece. It is evident however, from the many circumstances 

 enumerated, that this group must form a distinct family (the 

 Icacinacea) , and it will consist of the genera Icacina, Mappea 

 (Juss.), Apodytes, Rhaphiostyles, Stemonurus (identical with 

 Gomphandra), Leretia, Phlehocalymna (Griff.), Sarcostigma, Po- 

 raqueiba, Pcnnantia, Ptycopetalum, Pogopetalum, and Desmo- 

 stachys. 



I am aware of the objections that will be raised by some 

 botanists, who are averse to multiplying the present number of 

 orders, but it appears to me most important to the advancement 

 of science, to detect in the various natural groups of plants, a 

 few decisive characters, by which they can be readily distin- 

 guished, and this should be accomplished, even at the risk of 

 increasing the number of families : this indeed is a far less evil 

 than the opposite extreme, where, by reducing too much the 

 divisions of the system, the most opposite characters often be- 

 come blended in one group, and we thus lose sight of every use- 

 ful and well-defined line of demarcation. This inconvenience 

 was pointed out on a former occasion (Illustr. South Amer. 

 Plants, vol. i. p. 167), when I proposed the family of the Atro- 

 pacea, but I then suggested, that if this were felt to be an evil, 

 it might be counterbalanced, by classing in one immense family 

 the Scrophulariacece, Solanacece, Atropacece, &c., which all partake 

 of many similar general characters. In like manner the Celas- 

 tracea, Aquifoliacece, Icacinacece, and perhaps some others, might 

 be considered as suborders, but I am not yet prepared to define 

 the exact limits of such a group. The same observations will 

 equally apply to what I have said farther on, relative to the 

 Viscacea. 



We have now arrived at that point in this investigation, when 

 we can better understand the exact relation existing between the 

 Olacacea and the Santalacea, to which I have already alluded. 

 The details given of the structure of Cathedra and Liriosma en- 

 able us to comprehend more fully the true nature of the floral 

 parts seen in Santalacea. In the Olacacece we have observed 

 that the ovarium is always superior, and quite unconnected with 

 the real calyx, and that the cupshaped disk, which supports on 

 its margin the corolla and the stamens, is sometimes, though 

 not always, adnate with the ovarium, growing with it in such 



