CONTENTS. 



Transactions of the Society — 



PAGB 



I. — The Constituents of Sewage in the Mud of the Thames. 



By Lionel S. Beale, F.R.S., Treas. E.M.S. (Plates I.-IV.) Part 1 1 



II. — On the Mode of Vision with Objectives of Wide Aperture. 



By Prof. E. Abbe, Hon. F.R.M.S. (Figs. 1-7) .... „ 20 



III. — Observations on the Life-History of Stephanoceros Eich- 



hornii. By T. B. Rosseter, F.R.M.S. (Plate V. Figs. 1-3.) Part 2 169 



IV. — The President's Address. By Prof. P. Martin Duncan, 



F.E.S., V.P.L.S., &c 173 



v.— On the Mineral Cyprusite. By JulienDeby,C.E.,F.R.M.S. „ 186 



VI. — List of Desmidiese found in gatherings made in the 

 neighbourhood of Lake Windermere during 1883. By 

 J. P. Bisset. (Plate V. Figs. 4-7) , 192 



VII. — On the Formation and Growth of Cells in the Genus 



Polysiphonia. By George Massee, F.R.M.S. (Plate VI.) „ 198 



VIII. — On the Estimation of Aperture in the Microscope. By 



the late Charles Hockin, jun. (Plate VII.) Part 3 337 



IX. — Note on the Proper Definition of the Amplifying Power of 

 a Lens or Lens-system. By Prof. E. Abbe, Hon. F.R.M.S. 

 (Fig. 48) „ 348 



X. — On Certain Filaments observed in Surirella hifrons. By 



John Badcock, F.R.M.S. (Figs. 49 and 50) „ 352 



XL — Researches on the Structure of the Cell-walls of Diatoms. 



By Dr. J. H. L. Flogel. (Plates VIIL and IX.) .. ..Parti 505 



XII.— On a New Microtome. By C. Hilton Golding-Bird. (Figs. 



83 and 84) „ 523 



XIII. — On some Appearances in the Blood of Vertebrated Animals, 

 with Reference to the Occurrence of Bacteria therein. By 

 G. F. Dowdeswell, M.A., F.R.M.S., &c „ 525 



XIV. — On Protospongia pedicellata, a new compound Infusorian. 



By Frederick Oxley, F.R.M.S. (Figs. 85 and 86) . , .. „ 530 



XV. — On a New Form of Polarizing Prism. By C. D. Ahrens. 



(Figs. 87 and 88) „ 583 



XVI. — Researches on the Structure of the Cell-walls of Diatoms 

 {continued). By Dr. J. H. L. FlOgel. (Plates IX., X. 

 and XL and fig. 119) Part 5 665 



XVII.— On Drawing Prisms. By J. Anthony, M.D. Cantab., 



F.R.C.P., F.R.M.S. (Figs. 120-2) „ 697 



