332 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1914. 
strata has no reason for being different from the geology of the con- 
tinents save the inevitable restriction that necessitates the progres- 
sive evolution of all forces working on our planet. The present 
formation is the continuation of ancient formations disturbed by 
similar accidents. 
But here I come face to face with an objection about which I 
must say a word. Some standard treatises will confidently tell of 
the permanence of the great oceanic basins. Especially will you see 
in certain works which are in the hands of everyone the statement 
that the Pacific has always been an ocean. 
On what does this theory rest? Almost exclusively on the fact 
that our geologic strata contain no deposits in whick can be clearly 
identified any formations from great depths; for I do not consider 
as a valid argument the fact that the outline of the Pacific coasts 
seems formerly to have been marked by channels where coursed the 
marine floods of former ages. The first objection, on the contrary, has 
its value. In fact, if you asked me to cite a geologic stratum repre- 
senting a depth of 4,000 to 8,000 meters, I should be much embar- 
rassed to do so, although certain manganese deposits associated with 
radiolarians have sometimes been considered as belonging to a great 
depth. But I do not think that this is positive proof and here is the 
reason. First of all, it will be observed that the land has necessarily 
much oftener been subjected to movements of slight range, capable 
of causing emergence from depths of 50 to 100 meters, than to move- 
ments great enough to bring beds back to light from hollows of 
10,000 meters. These deep hollows stand by themselves and besides 
must always have constituted exceptional cases. Simple logic there- 
fore leads to the conclusion that the representative deposits in our 
strata must preferably come from littoral sediments or from slight 
depth. Abysmal deposits on any hypothesis must therefore be 
much rarer, unless there is in them a primary difference, a demarca- 
tion traced from the first day on the model of our planet. If these 
abysmal deposits appear to be lacking, that may be explained in two 
ways without necessarily concluding the indefinite persistence of the 
great oceanic hollows. It is either because we do not know how to 
recognize these deposits, transformed as they have been by diagen- 
esis and metamorphism in a movement of the crust which, by its 
very extent, has here reached the greatest violence, or else because 
they may have been disintegrated and carried off at the time of this 
violent emergence. 
I recognize that these arguments would be of little value if, on the 
other hand, all geology did not impress us with the idea that the 
seas have been constantly displaced on the surface of the earth, 
and not only such small seas as the Baltic, the North Sea, and the 
Mediterranean, which are the immediate prolongation of neighbor- 
