496 THE DEPTHS OF THE SEA. [CHAP. x. I 



of this I will quote -two passages in two consecutive I 

 anniversary addresses by Presidents of the Geological I 

 Society, and we may have every confidence that the j 

 statements of men of so great weight, made under I 

 such circumstances, indicate the tendency of sound 1 

 and judicious thought. Professor Huxley, in the 1 

 anniversary address for the year 1870, says : " Many 1 

 years ago 1 I ventured to speak of the Atlantic mud j) 

 as ' modern chalk,' and I know of no fact inconsistent I 

 with the view which Professor Wyville Thomson has ! 

 advocated, that the modern chalk is not only the \ 

 lineal descendant, so to speak, of the ancient chalk, ) 

 but that it remains, so to speak, in possession of the \ 

 ancestral estate ; and that from the cretaceous period j 

 (if not much earlier) to the present day, the deep sea j 

 has covered a large part of what is now the area of 

 the Atlantic. But if Globigerina and Terebratula \ 

 caput-serpentis and Beryx, not to mention other i 

 forms of animals and of plants, thus bridge over the j 

 interval between the present and the mezozoic 

 periods, is it possible that the majority of other i 

 living things underwent a sea-change into something \ 

 new and strange all at once ? " 



And Mr. Prestwich, in the presidential address for j 

 1871, says : " Therefore, although I think it highly j 

 probable that some considerable portion of the deep | 

 sea-bed of the mid- Atlantic has continued submerged : 

 since the period of our chalk, and although the more j 

 adaptable forms of life may have been transmitted in ; 

 unbroken succession through this channel, the im- I 

 migrations of other and more recent faunas may 

 have so modified the old population, that the original 



1 Saturday Eeview, 1858 : " Chalk, Ancient and Modern." 



