584 
APPENDIX. 
1823. Dr Yule read his Observations on the presumed Ana- 
March 22. . „ . ^ P 1 -r^ , . , IT 
logy oi certain Organs oi the Ijimbryo, m the several dis- 
tinct Races of Vascular Plants. The Secretary read a paper 
by James Wilson, Esq. on the Genus Mergus. Professor 
Jameson read Extracts of a Letter from Dr Oudney, 
Leader of the African Expedition, dated Mourzuk, 17th 
September 1822; likewise the first part of Mr Macgilli- 
vray's Remarks on the Specific Characters of Birds. 
April 5. The Secretary read an Extract from a Letter relative to 
the appearance of Pompeii, written by Lieutenant Boyd, 
R. N., and communicated by Mr Arnott ; also a Descrip- 
tion of a Reversed Species of Fusus, by Dr Fleming. Mr 
Greville then read Observations on the Formation of Lead- 
Spars, communicated by Mr Braid of Leadhills. And Mr 
Deuchar exhibited and explained some curious Experiments 
on Crystallisation. 
April 19. The Secretary read a paper by Dr Knox on the Ana- 
tomy of the Beaver ; and Observations by Mr Don on a 
new Natural Family of Plants, to be called Cobeaceae. Dr 
, Knox then read an Inquiry into the Original and Charac- 
teristic Differences of the Native Races inhabiting the 
extra-tropical part of Southern Africa. Professor Jameson 
gave an account of a communication from Dr Boue, dated 
Vienna, in which he controverts the late Observations of 
Professor Buckland of Oxford, in regard to the Secondary 
Formations of the Alps of Switzerland, and also detailed 
his Observations on the Pyrenees, and South of Germany. 
April 26, Mr Arnott read a paper, by Mr L. Edmondston, on the 
Black-billed Auk and Lesser Guillemot, and Professor 
Jameson described the specimens exhibited. Dr Knox 
read a paper on some Pcculiarilies of the Structure of the 
