l/ 



530 PRIMARY FACTORS OF ORGANIC EVOLUTION. 



1886. Ryder, J. A. Annual Report U. S. Commissioner of Fish 



and Fisheries for 18S4, pp. 981-1085, PI. IX. On the 

 Origin of Heterocercy, etc. 



1887. Ryder, J. A. American Naturalist, pp. 780-784. A Theory 



of the Origin of Placental Types, etc. 



1887. Cope, E. D. American Naturalist, pp. 985, 1060. The 



Perissodactyla. 



1888. Cope, E. D. Proceedings of the American Association for 

 the Advancement of Science, p. 254. On the Mechanical 

 Origin of the Sectorial Teeth of the Carnivora. 



1888. Cope, E. D. American Naturalist, p. 3. The Mechanical 

 Causes of the Origin of the Dentition of the Rodentia. 



1888. Cope, E. D. Proceedings of the American Philosophical 

 Society, p. 80. The Mechanical Origin of the Dentition 

 of the Amblypoda. 



1888. Ryder, J. A. American Naturalist, p. 547. The Several 



Functions of the Enamel Organ in the Development of the 

 Teeth of Mammals, and on the Inheritance of Mutilations. 



1889. Cope, E. D. American Naturalist, March. The Artiodac- 



tyla. (The elbow joint ; the zygapophyses.) 



1889. Cope, E. D. American Journal of Morphology, IIP, p. 137. 

 The Mechanical Causes of the Development of the Hard 

 Parts of the Mammalia. 



1889. Hyatt, A. Smithsonian Contributions to Knowledge, and 

 Memoirs cf the Museum of Comparative Zoology, Cam- 

 bridge, XVI , No. 3. The Genesis of the Arietida\ 



1889. Dall, W. H. American Journal Science and Arts, XXXVIII., 

 p. 445. Hinge of Pelecypoda and Its Development. 



1889. Osborn, H. F. Transactions American Philosophical So- 

 ciety, XVI., p. 531. (Published February, 1890.) The 

 Evolution of the Ungulate Foot ; The Mammalia of the 

 Uinta Formation. 



1889. Ryder, J. A. American Naturalist, pp. 218-221. The Po- 

 lar Differentiation of Volvox, etc. 



1889. Ryder, J A. American Naturalist, pp. 271-274. The Quad- 



rate Placenta of Scitirits hudsonius. 



1890. Ryder, J. A. Proceedings American Philosophical Society, 



XXVIII , pp. 109-159. The Origin of Sex, etc. 

 1890. Ryder, J. A. American Naturalist, pp. 376-378. The Pla- 



centation of the Hedgehog and Phylogeny of the Placenta. 

 1890. Packard, A. S. Proceedings Boston Society Natural His* 



