I08 THE STUDY OF SIX AND TEN MILLIMETER PIG EMBRYOS 



Myotome 



Ant. cardinal vein 



R. atrium 



Somatopleure 



Olfactory pL 



Descending aorta 

 Pharynx 



Pericardial cavity 



Bulbus cordis 



Telencephalon 



FIG. 108. Transverse section through the bulbus cordis and olfactory pits of a 6 mm. pig 



embryo. X 26.5. 



Spinal cord 



Descending aorta 

 Esophagus 



Sinus venosu. 

 Valve of sinus venos 



R. atriu 

 Atrio-ventricular foramen 



I nterventricular sept 



R. 



Somatopleur 



L. common cardinal vein 



Trachea 

 L. atrium 

 Septum I 

 L. ventricle 



I nterventricular foramen 

 Pericardial cavity 



FIG. 109. Transverse section through the four chambers of the heart of a 6 mm. pig embryo. 



X 26.5. 



