PLATE 3 



EXPLANATION OF FIGURES 



31 to 34 Four sections of livers of Aeanthias embryos of different ages, illus- 

 trating the changes in the hepatic cylinders; all X 400. 



31 Section of the liver of an embryo 16 mm. long (K.U.E.C. 547) ; iron 

 hematoxylin. 



32 Section of the liver of an embryo 20.6 mm. long ('H.E.C. 1494) ; iron 

 hematoxylin. 



33 Section of the liver of an embryo 32 mm. long (H.E.C. 1652); iron 

 hematoxylin. 



34 Section of the liver of an embryo (of Squalus sucklii) 95 mm. long (H.E.C. 

 1882); alum cochineal. 



306 



