PLATE 2 



EXPLANATION OF FIGURES 



25 to 27 Sections of hepatic tubules of Acanthias illustrating the process of 

 anastomosis; (fig. 36 represents a step between figs. 26 and 27). 



25 Early contact stage in anastomosis; from an embryo 13.3 mm. long (S.C. 

 18) ; alum hematoxylin. X 400. 



26 Fusion of tubules ; from an embryo 19 mm. long (S.C 3) ; alum hematoxylin. 

 X 400. 



27 P'stablishmcnt of connecting lumen between two anastomosed tubules. 

 From an embryo 19 mm. long (S.C. 2); alum hematoxylin. X 400. Graphic 

 reconstructions of these tubules, shown in cross section in figures 26 and 27, are 

 illustrated in figure 2, page 224. 



28 to 30 Sections of the external walls of lateral hepatic pouches of Acanthias 

 embryos illustrating the formation of the hepatic tubules. 



28 Formation of tubule ridges; from an embryo 8 mm. long (K.U.E.C. 

 545); iron hematoxylin. X 600. 



29 Early outpouching of individual tubules. From an embryo 10 mm. 

 long (S.C. 20) ; alum hematoxylin. X 400. 



30 Completely formed tubules at the time when anastomoses first appear; 

 from an embrj'o 13.3 mm. long (S.C. 18); alum hematoxylin. X 400. 



304 



