MICHIGAN ACADEMY OF SCIENCE. 
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troublesome and the scheme herewith presented is put forward with some 
misgivings on account of its manifest crudity, but it serves to bring 
ont important points and is therefore in use pending the devising 
of a better method or a better carrying out of this one. 
Briefly it is this : Mercator charts being found to be unsatisfactory 
on account of the distortion, and spherical projections being almost im- 
possible to draw, the continents have been moved about upon a globe 
and in the rearrangement photographed. Prom the photograph the 
continental outlines have been traced so that we secure a result some- 
what similar to a spherical projection. Upon this tracing as a basis the 
paleogeographic ideas of any author may be set forth. 
Herewith are presented adaptations on this basis of the views of von 
Ihering and Ortmann, and, as well as I have been able to interpret, of 
Scharff. These maps are submitted without argument, being intended 
to introduce the method and to gain some idea of the general relations 
of land and sea. without too great reliance on detail either of time or 
of conformation. The land connections are variously correlated by dif- 
ferent authors. Ortmann would retain some form of connection be- 
tween Europe, Greenland and America throughout Tertiary time. He 
would have South America united to Antarctica in the lower Tertiary, 
von Ihering would connect Brazil and Africa in the Eocene. Matthew 
terminates all trans- Atlantic connections before the Tertiary and cuts 
off South America from Antarctica by the middle of the Eocene. 
Hardly a feature of zoogeography or of geology rests upon a less 
satisfactory basis than intercontinental correlation and until the ele- 
ment of time can be more positively determined this must remain one 
of the difficulties of the theory, but it is precisely in this matter of 
correlation that the theory offers a new basis and a new hope for the 
future. 
