3°- 



[Proc. B.N.F.C. 



importance — The diatomaceous earths are largely used as polish- 

 ing powders, as sand for delicate castings in iron, in the manufac- 

 ture of dynamite, for boiler and pipe covering, and in many other 

 processes in the arts and manufactures. 



In the interesting discussion which followed Mr. W. J. Dakin, 

 AI.Sc, gave a short account of the distribution and seasonal 

 variations of marine diatoms. He pointed out that some of the 

 most important biological problems connected with the wonderful 

 see-saw of life in the ocean concerned the diatomacece. Thus in 

 the Irish Sea there takes place every year a sudden increase in the 

 number of diatoms present during the month ot April until the 

 water literally teems with these organisms. In perhaps four or 

 five days this huge increase drops off, until at the end of May 

 only a few diatoms are to be found, and this condition prevails 

 during the Summer months. What determines this extraordinary 

 maximum in Spring remains a mystery, as does also the cause of 

 their abundance in Arctic and temperate regions. The diatoms, 

 though exceedingly small, have been shown to play an important 

 part as the food of small crustaceans in the sea. These in turn 

 are the food of fishes, and so indirectly the diatoms are the food 

 of man. From the economic as well as the scientific point of 

 view therefore the diatoms are of considerable importance, and 

 what is required is a detailed study of their life-history and the 

 conditions under which they flourish. 



The following members also took part in the discussion — -The 

 Chairman, Mr. R. Welch, M.R.I.A., Mr. S. Wear, and Mr. 

 Bennett. 



"WITH THE BRITISH ASSOCIATION IN CANADA, 

 IN 1909." 



On Tuesday, 15th February, Dr. Dwerryhouse, Lecturer in 

 Geology in the University of Belfast, gave a lecture entitled 

 "With the British Association in Canada in 1909," the President, 

 Mr. N. H. Foster, M.B.O.U., in the chair. 



