xvi Proceedings. {February ^th, t^ij. 



Mr. D. Thoday, M. A., exhibited a capillary eudiometric 

 apparatus devised by Bonnier & Mangin, of Paris, for analysing 

 small volumes of air in experiments on the exchange of gases 

 between plants and the atmosphere. The apparatus was first 

 described in 1891 by Antert. The volume of air used is only 

 about 0.3 cc, and the complete analysis and subsequent washing 

 of the apparatus take about a quarter of an hour. Mr. Thoday 

 shewed how the apparatus is used and gave an account of his 

 critical investigation of sources of error to which the method is 

 liable and modifications of technique which he has been led to 

 introduce. The results finally obtained shew a degree of 

 accuracy which approaches very nearly to the highest expecta- 

 tion, a series of analyses giving percentages of CO2 and oxygen 

 in samples of air which differ from the mean by not more than 

 0.05 % of the total volume of air analysed. 



Mr. W. B. Brierley, M.Sc, read a paper entitled "The 

 Structure and Life-history of Lcptosphccria lemanea'." 

 This paper is printed in full in the Memoirs. 



General Meeting, February iSth, 1913. 



The President, Professor F. E. Weiss, D.Sc, F.L.S., 

 in the Chair. 



Mr. William Henry Sutcliffe, F.G.S., SJwre, Liitk- 

 borough., Lancashire^ was elected an ordinary member of the 

 Society. 



Ordinary Meeting, February :8lh, 1913. 



The President, Professor F. E. Weiss, D.Sc, F.L.S., 

 in the Chair. 



A vote of thanks was accorded to the donors of the books 

 upon the table. These included the following : — '^Proceedings 



