[ iv ] 
XII. On the Development and Morphology of Phylloglossum Drummondii. Bj 
Professor F. 0. Bower. , Communicated by W. T. Thiselton Dyer, 
FR.S . •••'•• page 665 
XIII. Residts deduced from the Measures of Terrestrial Magnetic Force in the 
Horizontal Plane, at the Royal Observatory, Greenwich, from 1841 to 1876. 
By Sir G. B. Airy, K.C.B., F.RS., late Astronomer Royal .679 
XIV. On Radiant Matter Spectroscopy. — Part II. Samarium. By William 
Crookes, F.R.S. .691 
XV. Researches on the Theory of Vortex Rings. —Part II. By W. M. Hicks, M.A., 
F.R.S., Principal and Professor of Mathematics and Physics in Firth College, 
Sheffield .^5 
XVI. On the Clark Cell as a Standard o} Electro-motive Force. By Lord 
Rayleigh, M.A., D.C.L., Sec. R.S .781 
Index to Volume 
801 
