282 PROGRESS OF SCIENCE IN THE CENTURY. 



and show how in the Triassic, for instance, there 

 was sea where there is now the great mountain belt 

 of the Euro-Asiatic continent, or how the great chalk 

 deposits of the Cretaceous are the analogues of the 

 deep sea Globigerina ooze of to-day. 



Summary. — One of the great discoveries of the 

 nineteenth century was that of the Deep Sea — utmost 

 a new world. The vast depths, the low temperature, 

 the abundant animal population and the deposits 

 ivhich accumulate on the floor have been the subject 

 of carCffid and fruitfid study, but the vastness of the 

 area makes it certain that much that is new still 

 awaits the explorer of the abysses. 



