CARDIAC LOOP IN RABBIT 



35 



Fig. 4 Model of the myocardium (dorsal view of the ventral wall) from a 

 rabbit embryo of nine days; H. E. C, Ser. 619. 1, bulboventricular canal; 2, 

 left shoulder; 3, left bulboventricular groove; 4, right shoulder; 5, right bulbo- 

 ventricular groove; 6, inward protrusions of the myocardium in a line directed 

 toward the center of the atrial canal; 7, sinus venosus. X 100. 



Fig. 5 Model of the myocardium (ventral view) from a rabbit embryo of 

 nine and one-half days; H. E. C, Ser. 565. 1, aortic branches; 2, bulb; 3, bulbo- 

 ventricular groove; 4, shoulder; 5, common ventricle; 6, right vitelline vein; 7, 

 left vitelline. X 100. 



