CONTENTS (continued). 



February 27, 1890. 



PAGE 



Croonian Lecture. — The Eelations between Host and Parasite in certain 

 Epidemic Diseases of Plants. By H. Marshall Ward, M.A., F.R.S., 

 late Fellow of Christ's College, Cambridge, Professor of Botany in the 

 Forestry School, Boyal Indian Engineering College, Cooper's Hill . . 213 



List of Presents 216 



On the Steam Calorimeter. By J. Joly, M.A., B.E., Assistant to the Pro- 

 fessor of Civil Engineering, Trinity College, Dublin (Plates 6, 7) . . 218 



A Milk Dentition in Orycteropus. By Oldeield Thomas, Natural History 



Museum (Plate 8) . . . . 246 



On the Effect of the Spectrum on the Haloid Salts of Silver. By Captain W. 



de W. Abney, C.B., R.E., D.C.L., F.E.S., and a. S. Edwards, C.E. . 249 



Published by Triibner and Co. 

 Royal «4to. pp. xiv-326, cloth. Price 21*. 

 OBSERVATIONS OF THE INTERNATIONAL POLAR EXPEDITIONS. 



1882-1883. 

 Fort R a e . 

 With 32 Lithographic Folding Plates. 

 A reduction of price to Fellows of the Eoyal Society. 



Published by Triibner and Co. 



In 1 vol., 4to. Pp. 500. With 6 Chromolithographs of the remarkable Sunsets of 

 1883 and 40 Maps and Diagrams. 



THE ERUPTION OF KEAKATOA AND SUBSEQUENT PHENOMENA. 



Report of the Krakatoa Committee of the Eoyal Society. 



Edited by Gr. J. Symons, F.E.S. 



Price 30*. To Fellows, 20*. 



HARRISON AND SONS, 45 & 46, ST. MARTIN'S LANE, W.C., 



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