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THE STUDY OF SIX AND TEN MILLIMETER PIG EMBRYOS 



Spinal cord 

 Notochord 



Ant. cardinal vein 



R. atrium 



Somatopleurc 



Olfactory pit' 



Myotome 



Descending aorta 

 'Pharynx 



Pericardial cavity 



Bulbus cordis 



Telcncephalon 



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



embryo. X 26.5. 



Spinal cord 



Myotome 



Descending aorta 

 Esophagus 



Sinus venosus 1 

 Valve of sinus venosus 



R. atrium 

 Atria-ventricular foramct 



Interventricular septum 



R. ventricle 

 Somatopleure 



L. common cardinal vein 



Trachea 

 L. atrium 

 Septum I 

 L. ventricle 



Intervenlricular foramen 

 Pericardial cavity 



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



X 26.5. 



