190 ANNJTEESAEY ADDKES3 



10. Geological. 



The late Sir Charles Lyell says, in the sixth edition of his 

 ' Elements of Geology ' (1865): " That white chalk is now forming 

 in the depths of the ocean, may now be regarded as an ascertained 

 fact, because the Olohigerina hulloides is specifically nndistinguish- 

 ablc from a fossil which constitutes a large part of the chalk of 

 Europe." He assumed that the Glohigerina inhabited the ooze on 

 the sea-bed. Edward Eorbes and other geologists had initiated and 

 adopted the same view that the Chalk was a deep-sea deposit. In 

 my Presidential Address to the Biological Section of the British 

 Association at the Plymouth Meeting in 1877, I ventured to 

 question the validity of this theory, and especially that which my 

 colleague and friend Sir Wyville Thomson started as to the " con- 

 tinuity of the Chalk" from the Cretaceous to the present period. I 

 there endeavoured to show that the Chalk differed in composition from 

 the Atlantic mud, and that the fauna of the Chalk formation repre- 

 sented shallow and not deep water. My view has, I am glad to say, 

 been to some extent admitted by Sir "Wyville Thomson in his ' Eeport 

 on the Scientific Results of the Yoyage of H.M.S. "Challenger," ' 

 when he speaks (pp. 49 and 50) of the belt of " shallower water " 

 during the Cretaceous period. At all events, Mr. Wallace has lately 

 accepted and confirmed my view."^' It is highly probable that the 

 Gault which underlies the Chalk and is the lowest member of the 

 Upper Cretaceous formation, was a deep-water deposit, because it 

 abounds in small shells of the Area and Corhula families, as well as 

 in Ammonites and other free-swimming Cephalopods. 



Mr. Solhis, indeed, in his paper " On the Flint jSTodules of the 

 Trimmingham Chalk," f says that he believes that some deep-sea mud 

 is analogous with the chalk. He is aware that the former contains 

 siliceous organisms and the latter none ; and he supposes that the 

 flints had been in some way derived from these organisms. But 

 how flints originated and were formed is still a vexed question. Mr. 

 Sollas is, perhaps, the best authority on sponges ; but he states 

 (page 444) that "the bottom-water of the sea is remarkably free 

 from organic matter." This statement does not agree with the 

 analyses of the bottom-water of the sea which were made by Mr. 

 Lant Carpenter, Dr. Erankland, and Mr. Buchanan, the chemist of 

 the ' Challenger,' nor with the observations of Sir "Wyville Thomson 

 in his ' Depths of the Sea,' in which he says (page 46) : " the bottom 

 of the sea is a mass of animal life." 



* ' Island Life.' t ' Ann. and Mag. Nat. Hist.,' Dec. 1880. 



