B. C 



Vent. 



J. C. WATT del. 



1. Ventral view of wax-plate reconstruction of the muscular tube of the heart in Embryo VI. 



2. Dorsal view of wax-plate reconstruction of the muscular tube of the heart in Embryo VI. 



8. Dorsal view of wax-plate reconstruction of the endothelial tube of the heart in Embryo VI. 



4. Lateral view, from the left, of wax-plate reconstruction of the endothelial tube of the heart in Embryo VI. 



For abbreviations see page W 



