The recapitulation theory and human infancy Davidson, Percy E. (Percy Erwin), 1874- creator text book New York city Teachers college, Columbia university 1914 1914
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ENG Published also as thesis (PH. D.) Columbia university, 1914. Embryology Embryology, Human Evolution QH371 .D2 Contributions to education, no. 65 https://www.biodiversitylibrary.org/bibliography/57554 3957739 15004226 10.5962/bhl.title.57554