PLATE 4 



EXPLANATION OF FIGURE.'- 



45 Anterior view of the pancreas and ventral pancreatic ducts of a 13 mm. 

 embryo. X 60. 



46 Anterior view of the pancreas and ducts of a 15 mm. embryo. X 60. 



D., duodenum V.jxni., ventral pancreas 



D.pan., dorsal pancreas Y, yolk-gut 



G.B., gall-bladder D.cJr I., ductus clioledochus 



Lt.pan.d., left ventral pancreatic duct V.j)nit.(i.. ventral pancreatic ducts. 



/?/. pan. (/., right ventral pancreatic duct l'^)r (ither aljbreviations, see figure45. 



St., stomach 



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