as distinguished from the Symplocacese. 133 



sition of sclerogen within or around its cells, and that, by the 

 spreading of the raphe under its endodermal surface, the latter 

 has become almost isolated from it, in the form of a separable 

 opake pellicle. The existence of the micropylar opening-, closed 

 externally by the cicatrix before described, is a still further con- 

 firmation of the origin of the bony tunic of the seed in the 

 Siijracinece. 



The essential differences observable in the floral structure of 

 the two families under consideration now remain to be considered. 

 I have already alluded to the facts long since given in Prof. 

 Lindley^s 'Vegetable Kingdom^ (p. 593 a) : these details, as 

 before mentioned, were subsequently combated by Dr. Asa Gray; 

 and as the reasoning he employed on that occasion is highly 

 applauded, to the exclusion of my inferences, in a criticism in 

 the ' Kew Journ. Bot/ vii. 139, it is necessary to test the value 

 of the evidence on both sides. In doing this, I gladly express 

 my full appreciation of the high merits of the distinguished 

 Professor, which are so deservedly eulogized in the review just 

 mentioned : my object in this is not to arraign the remarks of 

 one so pre-eminent for the clearness of his views and the general 

 accuracy of his observations, but to defend the evidence I had 

 previously endeavoured to establish, the truth of which he has 

 denied. I will therefore confine myself solely to the facts thus 

 impugned in his ' Notes on Vavcea/ respecting the co-ordinal rela- 

 tion of Styrax and Symplocos. The grounds upon which this 

 relationship is there defended are reducible to six heads* : — 

 1. It is urged, that, as an inferior ovary is common to both 

 groups, this character affords no distinguishing mark of the 

 Symplocacece, 2. The aestivation of the corolla establishes no 



would necessarily occur if that coating had formed any part of the original 

 carpellary leaves. Gaertner demonstrates the existence of a similar peri- 

 pherical thick envelope around the elastic cocci of the EupJiorbiacece (De 

 Fruct. Croton, pi. 107 j Jatropha, pi. 108, 109, &c.) : these cocci contain- 

 ing manifest nervures, show us that each is an ossified, distinct, and entire 

 carpel ; their adjacent sides, which split from one another, have no indica- 

 tion of the intervention of any portion of the peripherical envelope, which 

 would infallibly have taken place had that external portion ever belonged 

 to the normal carpels. DeCandolle also alludes to the instance of Pceonia 

 Moutan {loc. cit. p. 40, et Syst. i. 388), where the ovary, from the expan- 

 sion of the torus or disk, becomes covered by a fleshy membranaceous 

 urceole which completely surrounds it, and through the perforated apex 

 of which the stigma is exserted ; this is at first quite free, but it afterwards 

 appears to form part of the fruit. To this source we may attribute the 

 origin of the fleshy covering of many fruits, analogous to the instance of 

 Nuphar ; and we must consider the nut of the Almond as the growth of 

 the entire carpel, and its fleshy covering as an emanation from the torus, 

 confluent with it. 

 * Mem. Amer. Acad, 2nd ser. v. 333, in a note. 



