678 “ REVIEWS AND BOOK NOTICES. 
aware Professor Dana was the first * to call attention to this pop- 
ular fallacy, which gives rise to so much crude theorizing to 
account for the present distribution of life and land on the surface 
of the globe. He shows from the fact “ that the sediment or débris 
from a shore is almost. wholly thrown back by the waves against 
the land where it originated, or over its submerged part in the 
shallow waters, and that is not transported away to make deep 
sea formations,” the important conclusion that * lands separated 
by a range of deep ocean cannot supply one another with material 
for rocks. The existence of an Atlantic ocean continent—an At- 
lantis—-has sometimes been assumed in order to make it a source 
of the mud, sand, and gravel, out of which the thick sedimentary 
formations of the Appalachian region of North America were made. 
But if this Atlantis were a reality, there would still have been 
needed, in addition to the presence of such an ocean continent, a 
set of freight carriers that could beat off the waves from their 
accustomed work, and push aside the ordinary oceanic currents; 
or else Atlantis would get back all its own dirt.” 
Professor Dana reasons from the existence of a Jurassic 
reef in England, that the “ Gulf Stream has had, from the Jurassi¢ 
period in geological history onward, the same kind of influence 
on the temperature of the north Atlantic ocean which it now has. 
Before the Cretaceous period began the waters cooled somewhat, 
as there were no coral reefs in the British Cretaceous se, though 
as late as the Miocene Tertiary, there were reef corals in the seas 
of northern Italy. 
coral 
e Atlantic, of any 
absence from the American coast of th 
als, see 
coral reefs of the Cretaceous beds, and of any reef cor 
to show that the oceanic temperature off this coas 
able for such corals ; and if so, then the li 
least 20° further north on the European side of the aer mem 
by similar facts. + Qalitic 
the Gulf Stream had its present position and force m gam 
Cretaceous, and Tertiary times, then the ocean had, throug 
these i anic character; 
eras, its present extension and oce 
* Proceedings Amer. Assoc. Adv. Science, 1856. 
