46 



H. VON W. SCHULTE 



flat : the cardiac aiilages lie in the same plane as the neural tube 

 and are separated by a wide interval. In the embryo of 11 

 somites (fig. 3) they are ventral to the closed foregut and their 

 proximal or bulbar ends are close together. At 12 somites 



Fig. 1. Reconstruction of compact mesoderm of cut embr3-o of eight pairs of 

 somites. Columbia Collection, No. 588. X 180. Reduced one-half. Dorsal view 

 the parietal mesoderm has been exsected to show topography of parietal cavity. 

 1, Parietal cavity; 2, pericephalic cavity; .3, parietal recess; 4, myoepicardial 

 mantle; 5, oblique groove dividing mantle into mesal and lateral protions; 6, 

 retrocardiac plate; 7, jirecardiac plate. 



