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THE AMERICAN NA TURALIST. [Vol. XXXVII. 



There exists .«n* largest axis of the earth, ending at two points 

 under the equator, and this is due to the fact that the diameter of 

 the equatorial belt, which is larger than any other, is increased by 



one side, and in Sumatra on the other. 



These two points, according to Reibisch and Simroth. were situated 

 under the equator throughout all of the earth's history, while all other 

 points of the present equator oscillate toward the north and south, 

 that is to say, they shift their position in consequence of a slow oscil- 

 lation of the poles in a direction marked by a meridian that goes 

 through Bering Sea on the one side, and through Europe and Africa 



Reibisch tries to support his views by a collection of facts show- 

 ing repeated subsidence and elevation of certain parts of the earth's 

 surface : this demonstration, however, is entirely insufficient to found 

 upon it a theory of this importance, and moreover, the burden of the 

 proof does not rest with Geology, but with Physics and Astronomy. 

 The latter branches have been entirely neglected by Reibisch as well 

 as Simroth, and thus their theory of this peculiar " oscillation " of the 

 Poles lacks proper support, we may even say, has no support at all, 

 since the geological evidence introduced by Reibisch is by far too 



Now, this assumption of an oscillation of the Poles in a straight 

 line, the North Pole moving alternately toward Europe and toward 

 Bering Strait, of which movement the earth-axis from Ecuador to 



problems of the earth's history and of the distribution of animals. 



It is hardly worth while to discuss Simroth's ideas in extenso, since 

 the zoogeographical material introduced by him is far from being 

 adequate. Generally, we may say that the facts quoted are indiffer- 

 ent with respect to his theory, sometimes the facts are misunderstood, 

 and in other cases they are directly incorrect or even absurd. The 

 same is true of the facts quoted from Geology or Physical Geography, 



