Proceedings at the Meetings. 179 



2. On the rate of recombination and. the size of gaseous ions. By 

 J. J. Thomson, M.A., Cavendish Professor of Experimental Physics. 



3. Some physical properties of Sodium Vapour. By P. V. Bbvan, 

 M.A., Trinity College. 



4. A null method of measuring small ionizations. By N. R. 

 Campbell, B.A., Trinity College. 



5. The reflexion of Sound at a Paraboloid. By Rev. H. J. Sharpe, 

 M.A., St John's College. 



May 15th, 1905. 

 In the University Botanical Laboratory. 



Professor Marshall Ward, President, in the Chair. 

 The following were elected Fellows of the Society : 



T. G. Bedford, M.A., Sidney Sussex College. 



C. Chittock, B.A., Trinity College. 



J. Aldren Wright, M.D., Sidney Sussex College. 



The following Communications were made : 



1. Exhibition of Lantern Slides of Fungi. By H. Marshall 

 Ward, Sc.D., Professor of Botany. 



2. Infection phenomena in various species of Uredinese. By 

 I. B. P. Evans, Sidney Sussex College. (Communicated by Professor 

 Marshall Ward.) 



3. The abortive development of the Pollen in certain cross-bred 

 Sweet Peas. By R. P. Gregory, M.A., St John's College. 



4. Crosses between fully fertile varieties of Barley and varieties 

 bearing unisexual and sexless flowers. By R. H. Biffen, M.A., 

 Emmanuel College. 



5. The Seed-bearing Habit in the Lyginodendreje. By E. A. N. 

 Aruer, M.A., Trinity College. (Communicated by Professor Marshall 

 Ward.) 



6. Experiments on penetrating Radiation. By H. L. Cooke, 

 Emmanuel College. 



