400 SCOTT. [Vol. V. 



crenellirte Nebenhocker und Warzen abhangig ist von der 

 Ernahrung des Thieres " (Schweineschadel, pp. 102, 103). 



I do not wish to be understood as in any way deprecating the 

 extremely candid, fair, and open-minded criticism to which Pro- 

 fessor Morgan has subjected the evidence drawn from the study 

 of American fossils ; but I cannot consent to be bound by 

 the admissions of members of the "American school." While 

 I freely grant that the evidence presented in the foregoing 

 pages in favor of mechanical factors in evolution is not con- 

 vincing or conclusive, I think it may fairly claim to afford some- 

 thing more than "a presumption in favor" of such factors. 



Princeton, October 12, 189 1. 



LIST OF PAPERS CITED. 



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 1872. 



2. Baur, G. On Intercalation of Vertebrae. Journal of Morphology, Vol. 



IV., p. 331. 



3. Boas, J. E. V. Zur Morphologie d. Magens der Cameliden und der 



Traguliden, etc. Morphologisches Jahrbuch, Bd. XVI., p. 494. 



4. Claus, C. Ueber die Werthschatzung der natiirlichen Zuchtwahl, etc. 



Vienna, 1888. 



5. Cope, E. D. On the Origin of Genera. Proceedings Academy Natural 



Sciences. Philadelphia, 1868. p. 242. 



6. Id. — On the Extinct Vertebrata of the Eocene of Wyoming. Sixth Ann. 



Rep. U.S. Geol. Survey of the Territories, p. 545. 



7. Id. — The Artiodactyla. American Naturalist, Vol. XXII., p. 1079. 



8. Id. — Report upon the Extinct Vertebrata obtained in New Mexico. 



Rep. U. S. Geograph. Surveys west of 100th Merid., Vol. IV., Pt. 2. 



9. Id. — Tertiary Vertebrata. Rep. U. S. Geological and Geograph. Survey 



of the Territories , Vol. III. 



10. Id. — On the Structure of the Feet of the Extinct Artiodactyla of North 



America. Proceedings American Association for the Advancement 

 of Science. 1884. p. 482. 



11. Id. — The Perissodactyla. American Naturalist, Vol. XXL, pp. 985, 1060. 



12. Dall, W. H. On the Hinge of Pelecypods and its Development. 



American Journ. Science and Arts, 3d Ser., Vol. XXXVIII. , p. 445. 



13. Id. — On Dynamic Influences in Evolution. Washington, 1890. 



14. De Candolle, A. Histoire des Sciences et des Savants, etc. Geneva, 



1885. 



15. Eimer, G. H. T. Die Entstehung der Arten, etc. Jena, 1888. 



16. Filhol, H. Notes sur quelques Mammiferes Fossiles. Lyons, 188 1. 



