Linmean Society. 363 



continuous with the lining membrane. The cavity of each follicle, 

 therefore, communicates with the exterior through the centre of this 

 process, and the aperture is thus guarded by a kind of circular valve 

 permitting the escape of secreted matters, but effectually preventing 

 the entrance of fluid from without. 



Some considerations are next offered in support of the view 

 adopted as to the functions of these vascular appendages. 



Lastly, on the question whether the peculiarities of structure re- 

 cognized respectively in A''. Pompillus and N. umb'dicatus are suflS- 

 cient to establish a difference of species, or are attributable merely to 

 variety, the author observes, that any tendency in a being to revert 

 to an original type, when such has been determined, betrays variety; 

 but tliis tendency is never manifested in the Nautili under consider- 

 ation by the occasional occurrence of specimens presenting charac- 

 ters which place them intermediately between N. Pompilius and 

 A^. umbilicatus. Having visited the Fijii Islands since he formerly 

 wrote on N. Pompilius, he finds that the umbilicated Nautili are not 

 known to the natives, although iV. Pompilius is very plentiful ; but at 

 Fatuna or Wallis's Island, where both are found, the people recog- 

 nize the difference between them depending on the presence or 

 absence of umbilical pits. On this the author remarks, that although 

 particular localities, with all attending circumstances, may favour 

 the production of varieties, yet the permanence of the distinctive 

 characters of these Nautili without symptom of amalgamation, and 

 the discovery of a female specimen of N. umbilicatus, are strong 

 arguments in support of the view that they are distinct species, 

 though very closely allied. 



LINNJEAN SOCIETY. 



June 20, 1854. — Thomas Bell, Esq., President, in the Chair, 

 Read the commencement of a paper " On the Structure of the 

 Seed and peculiar form of the Embryo in the Clusiacea," By John 

 Miers, Esq., F.R.S., F.L.S. &c. 



'I'he author stated it to be his object to direct the attention of bo- 

 tanists to the structure of the seed, and particularly of the embryo 

 in this family, the nature of which had been hitherto quite misun- 

 derstood. During his residence in Brazil he had made several ob- 

 servations on the Clusiacea, which he hoped would assist in defining 

 the characteis and limits of the genera, hitherto very imperfectly 

 described. These more general remarks would be reserved for a 

 future occasion, his object being now confined, as a matter of primary 

 importance, to the consideration of the seminal structure observable 

 in this family. 



He began by tracing a history of the facts and conclusions re- 

 corded on the subject. The earliest is that of Jussieu in 1789, where, 

 in his ordinal character of the Gutti/era, he states that the embryo 

 is erect, without albumen, and with hard corky cotyledons, a cha- 

 racter probably drawn only from Calophyllum. Gaertner next figured 

 the analysis of three species of Garcinia, and described the seed as 



