THE 



CANADIAN RECORD 



OF SCIENCE. fulBRAf 



VOL. II. JANUARY, 1887. NO. 5. 



Presidential Address before the British Asso- 

 ciation for the Advancement of Science, 

 Sept. 1886. 



By Sir J. William Dawson, C.M.G., M.A., LL.D., F.R.S., F.G.S., 



Principal and Vice-Chancellor of McGill University, Montreal, Canada. 



(Concluded.) 



We may also note a fact which I have long ago insisted 

 on, 1 the regular pulsation of the continental areas, giving us 

 alternations in each great system of formations of deep-sea 

 and shallow-water beds, so that the successive groups of for- 

 mations may be divided into triplets of shallow- water, deep- 

 water, and shallow-water strata, alternating in each period. 

 This law of succession applies more particularly to the for- 

 mations of the continental plateaus, rather than to those of 

 the ocean margins, and it shows that, intervening between 

 the great movements of plication, there were subsidences of 

 those plateaus, or elevations of the sea bottom, which allowed 



1 Acadian Geology, 1865. 



18 



