AUTHOR S ABSTRACT OP THIS PAPER 

 ISSUED BY THE BIBLIOGRAPHIC SERVICE 



THE EFFECT OF THE HEART-BEAT UPON THE 



DEVELOPMENT OF THE VASCULAR 



SYSTEM IN THE CHICK 



W. B. CHAPMAN 



Anatomical Laboratory of the University of Missouri 



SEVENTEEN FIGURES 



CONTENTS 



I. Introduction 175 



II. Review of literature * 176 



III. Method of investigation 178 



IV. Description of the extra-embryonic vascular system of embrj^os studied 180 

 V. A short description of the embryos 196 



VI. Mention of results obtained in a number of operations which were 



only partially successful 196 



VII. Discussion 198 



VIII. Summary 202 



IX. Literature cited 203 



I. INTRODUCTION 



At the time the circulation begins in the chick, the embryo 

 possesses a number of relatively large blood vessels. Thoma 

 ('93) mentions that the paired dorsal aortae are present, and in 

 a schematic drawing (p. 32) shows them connecting, anteriorly, 

 through capillaries with the heart, and, posteriorly, extending 

 into the capillary net of the extra-embryonic region. 



Miss Sabin ('17) in a monograph published recently, states 

 that, in addition to the dorsal aortae, the duct of Cuvier, the 

 cardinals, and several neural vessels have formed. These are 

 represented in plate 1, figures 2 and 3, and in plate 2, figures 1 

 and 2 of the monograph, which also show the primitive anterior 

 vitelline veins. She describes the vessels of the extra-embryonic 

 region as an extensive capillary plexus which connects with the 

 heart and dorsal aortae of the embryo. Quoting in part, she 



175 



