CONTRIBUTIONS TO EMBRYOLOGY, No. 68. 



TRANSFORMATION OF THE AORTIC-ARCH SYSTEM DURING THE 

 DEVELOPMENT OF THE HUMAN EMBRYO. 



By E. D. Conudon, 



Division of Anatomy, Leland Stanford Junior University, 

 and the Department oj Embryology, Carnegie Institution of Washington. 



With three plates and twenty-eight text-figures. 



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