PLATE IX 



EXPLANATION OF FIGURES 



12 Reconstruction (after Born) of veins in the lumbar region of a 21-mm. 

 cat embryo. Lateral aspect, right side. Periureteric venous ring, through which 

 ureter passes, present on right side. Coll. of P. and S. Embryological Collection, 

 no. 242. 



13 Reconstruction (after Born) of veins in the lumbar region of a 21-mm. 

 cat embryo. Lateral aspect, left side. Coll. of P. and S. Embryological Collec- 

 tion, no. 242. 



74 



