VI 



PAGE 



Studies on Enzyme Action. XIX. — Urease : a Selective Enzyme. II. — Observa- 



tions on Accelerative and Inhibitive Agents. By H. E. Armstrong, F.E.S., 



M. S. Benjamin, and Edward Horton 328 



A Preliminary Note on the Fossil Plants of the Mount Potts Beds, New Zealand, 

 Collected by Mr. D. G. Lillie, Biologist to Captain Scott's A ntarctic Expedition 

 in the "Terra Nova." By E. A. Newell Arber, M.A., Sc.D., F.G.S., F.L.S., 

 Trinity College, Cambridge, University Demonstrator in Paleobotany. Com- 

 municated by Prof. T. McKenny Hughes, F.B.S. (Plates 7 and 8) 344 



On the Nature of the Toxic Action of Electric Discharge upon Bacillus coli communis. 

 By J. H. Priestley and B. C. Knight. Communicated by J. Bretland Farmer, 

 F.E.S 348 



Experiments on the Kidneys of the Frog. (Preliminary Communication.) By 

 F. A. Bainbridge, S. H. Collins, and J. A. Menzies. Communicated by Prof. 

 C. J. Martin, F.E.S 355 



The Effect of the Lability (Eesilience) of the Arterial Wall on the Blood Pressure 



and Pulse Curve. By Leonard Hill, F.E.S., and Martin Flack 365 



On the Probable Value to Bacillus coli of " Slime " Formation in Soils. By Cecil 



Eevis. Communicated by Sir J. E. Bradford, K.C.M.G., Sec. E.S 371 



Variation in Bacillus coli. — The Production of Two Permanent Varieties from one 

 Original Strain by means of " Brilliant Green." By Cecil Eevis. Communi- 

 cated by Sir J. E. Bradford, K.C.M.G., Sec. E.S 373 



No. B 589.— June 12, 1913. 



Further Eesearches on the Extrusion of Granules by Trypanosomes and on their 

 Further Development. By W. B. Fry, Major E.A.M.C., and H. S. Eanken, 

 M.B. (Glasg.), M.E.C.P. (Lond.), Captain E.A.M.C. (With a Note on Methods 

 by H. G. Plimmer, F.E.S.) Communicated by H. G. Plimmer, F.E.S. 

 (Plates 9-11) 377 



Morphology of Various Strains of the Trypanosome causing Disease in Man in 

 Nyasaland. — The Wild-game Strain. By Surgeon-General Sir David Bruce, 

 C.B., F.E.S., A.M.S. ; Majors David Harvey and A. E. Hamerton, D.S.O., 

 E.A.M.C. ; and Lady Bruce, E.E.C 394 



Morphology of Various Strains of the Trypanosoma causing Disease in Man in 

 Nyasaland. — The Wild Glossina morsitans Strain. By Surgeon-General 

 Sir David Bruce, C.B., F.E.S., A.M.S. ; Majors David Harvey and A. E. 

 Hamerton, D.S.O., E.A.M.C. ; and Lady Bruce, E.E.C 408 



Infectivity of Glossina morsitans in Nyasaland. By Surgeon-General Sir David 

 Bruce, C.B., F.E.S., A.M.S. ; Majors David Harvey and A. E. Hamerton, D.S.O., 

 EA.M.C. ; and Lady Bruce, E.E.C 422 



The Excystation of Culpoda cucullus from its Eesting Cysts, and the Nature and 

 Properties of the Cyst Membranes. By T. Goodey, M.Sc. (Birm.1, late 

 Mackinnon Student of the Eoyal Society. Communicated by A. D. Hall, F.E.S. 427 



Protostigmata in Ascidians. By A. G. Huntsman, B.A., M.B., Biological Depart- 

 ment, University of Toronto. Communicated by Prof. A. B. Macallum, F.E.S. 440 



