CONTENTS. Ill 



PAGE 



Art. XVII. On the Paleeohydrography and Orography of the 

 Earth's Surface, or the probable position of Waters 

 and Continents, as well as the probable Depths of 

 Seas, and the absolute Heights of the Continents 

 and their Mountain-Chains during the different geo- 

 logical periods. By M. Ami Boue'. Communi- 

 cated by the Author, . . . . .298 



XVIII. On Animal and Vegetable Fibre, as originally 

 composed of Twin Spiral Filaments, in which every 

 other structure has its origin : a Note shewing the 

 confirmation by Agardh, in 1852, of Observations 

 recorded in the Philosophical Transactions for 1842. 

 By Martin Barry, M.D., F.R.S.E. Communi- 

 cated by the Author, . . . . .317 



XIX. On the Penetration of Spermatozoa into the Interior 

 of the Ovum : a Note, shewing this to have been 

 recorded as an Established Fact, in the Philosophi- 

 cal Transactions for 1843. By Martin Barry, 

 M.D., F.R.S.E, (Read before the Royal Society 

 of London, March 17, 1853). Communicated by 

 the Author, ....... 326 



XX. Researches in Embryology : a Note supplementary to 

 Papers published in the Philosophical Transactions 

 for 1838, 1839, and 1840, shewing the confirma- 

 tion of the principal facts there recorded, and point- 

 ing out a correspondence between certain Structures 

 connected with the Mammiferous Ovum and other 

 Ova. By Martin Barry, M.D., F.R.S., F.R.S.E. 

 Communicated by the Author, . . . 327 



XXI. On the Colour of Hair. By Dr Allen Dalzell. 



Communicated by the Author, . . ,329 



