Mr. J. Miers on the Affinities of the Olacacese. 129 



between the cells, at the axis, is almost complete, with the excep- 

 tion of a small portion at the summit, and this is only distinguish- 

 able under careful examination : the suspension of the ovules is 

 from a short and free central placenta that rises above the ab- 

 solute union of the dissepiments, in the very top of the ovarium, 

 and the partitions about this spot, though they all converge as 

 far as, and even touch the central placentary column, are yet 

 really free from it. Although the five cells are here completely 

 established throughout the entire length of the ovarium, still for 

 a very short distance at the apex, there exists a communication 

 between the cells, through the almost imperceptible chinks exist- 

 ing around the margins of such apical portions of the dissepiments 

 as are really disconnected with, although touching the placentary 

 column. The definition of Ad. Jussieu* of ^^ loculis ad apicem 

 inter se perviis," though quite true, is not a correct expression 

 of the structure of the ovarium of Hwnirium, This offers much 

 support to the views of Mr. Bentham in regard to the affinity of 

 the HumiriacecR with the OlacacecEj but in other respects there 

 seems little relation between the two families; for if in the ovarium 

 of Humirium, the confluence of the dissepiments had been com- 

 pleted about the central placentary column to the very summit, 

 the position of the Humiriacece in the system would have been 

 close to the Aquifoliacece. From the structure of the ovarium 

 and other characters, the conclusion now appears to me irresist- 

 ible, that wherever the Styracem may be stationed in any natural 

 arrangement, the HumiriacecB must be placed in contiguity with 

 them. The Humiriacece will therefore form one of those osculant 

 relations, existing everywhere in nature, which can only be re- 

 presented by the circular system, and never by any linear 

 arrangement; in the former method the Cionospermce would 

 touch the DryadeSj through Humiriunij while in the linear system 

 their location will fall to a distance. The position of the Humi- 

 riacece has never been satisfactorily determined: Von Martins, 

 who first suggested the order in 1826, considered it allied to 

 Meliacece, though doubtfully : Jussieu, in entertaining the same 

 view, had similar misgivings in regard to this affinity. Dr. 

 Lindley, in his ' Introduction to Botany,^ held them more nearly 

 related to the Aurantiacce, and Endlicher placed them at the 

 head of a class called Hesperides, in association with the Meliacece j 

 Aurantiacce, &c. Meissner stationed them also in the Hesperides 

 of Endlicher, adding at the same time to this class, the Olacacece ; 

 and finally. Dr. Lindley in his ' Vegetable Kingdom ' renounces 

 his former views, and fixes them in a most singular association 

 with the Ericacece, Epacridacece, Monotropaceee, &c. Mr. Bentham 



* Flov. Bras. Merid. A. St. Hilaire, vol. ii. p. 88. 

 Ann. §• Ma(^. N. Hist. Ser. 2. Vol. ix. 9 



