



-vh. 



Fig. I . Veins of the Wolffian body in an embryo pig 9 mm. long. 

 Fig. 2. Veins of the Wolffian body in an embryo pig 8 mm. long. 

 Fig. 3. Veins of the Wolffian body in an embryo pig I I mm. long. 

 Fig. 4. Veins of an embryo pig 23 mm. long. 

 The detailed description of the figures will be found on pages 31, 32. 



