THE 
AMERICAN NATURALIST 
Vor. XXVI. June, 1893. 318 
RECENT RESEARCHES UPON THE SUCCESSION OF 
THE TEETH IN MAMMALS. 
By Henry FAIRFIELD OSBORN. 
While American paleontologists have been making rapid 
advances in the phylogenetic history of mammalian teeth, 
the English have made notable additions to our comparative 
anatomical knowledge, and the Germans to the embryogene- 
sis. The recent studies of Kükenthal, Röse and Taeker in 
the discovery of the complete double or milk dentition in the 
Marsupials, and in the discussion of its relation to that of the 
reptiles, also in the ontogenesis of the crowns of the teeth 
among the Cetaceans, Edentates, Primates and Ungulates are - 
of the greatest interest and importance. They involve a 
complete revolution in our ideas as to the interpretation of the 
dentition in the three orders first mentioned above. 
The latter authors are perhaps inclined to lay too great 
stress upon the testimony of ontogenesis in the order of 
appearance and consequent homologies of the mammalian 
cusps, and Rése’s work is to a certain extent rendered less 
useful by the fact that he has substituted the conclusions of 
ontogeny for those based upon the more certain foundations of ` 
Phylogeny. It isa subject of congratulation, however, that 
ese authors, who constitute the rising school in Germany, 
Tecognize the value of the paleontological work done in this 
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