FUSION OF CARDIAC ANLAGES IN THE CAT 



()9 



concavity of the loop (fig. 15). Elsewhere only a partition of 

 endothelium separates the ventricles. 



Fig. 15 Section through ventricles of the same embyro. X 125. Reduced 

 one-half. 1, Area of coalescence of ventricles; 2, interval between endothelial 

 tubes; 3, middle cardiac plate; 4, atrium. 



Caudad the area of union between the omphalo-mesenteric 

 veins has increased and extends upon the terminal portion of 



