242 E. A. BAUMGARTNER 



its position at this stage one could easily be led to such a 

 conclusion. 



The gall-bladder of a 20 nun. embryo shows a very distinct 

 dorso-ventral increase in diameter (fig. 11). With this there 

 has been a marked cranio-caudal lengthening (fig. 43). The 

 relative size of the gall-bladder is now greater. As before indi- 

 cated, the cystic duct is here again nearer the anterior end, it 

 extends towards the left and now distinctly ventralward (fig. 11). 

 A right lateral and slightly ventral view of the gall-bladder is 

 shown in figure 43. 



In a 35 mm. embryo (fig. 44) the vertical diameter of the gall- 

 bladder has greatly increased. The cystic duct is now in the left 

 anterior ventral end extending ventrally and to the left. In a 

 45 mm. embryo the gall-bladder has the same general shape as 

 in the preceding, and the cystic duct has not changed in position 

 (fig. 12). 



In a graphic reconstruction of the biliary apparatus of a 10 

 cm. Amblystoma the cystic duct extends to the left, somewhat 

 ventrally and anteriorly (fig. 16). The gall-bladder is pear 

 shaped (fig. 13) with its large, blind end projecting slightly dor- 

 sally and to the right but mainly caudal ward. 



/. Summary of the development of the biliary apparatus. In 

 summarising the development of the hepatic ducts a table of 

 the ducts as found in the various models will bring out more 

 clearly their relations to the main duct. Table 3a to 3d shows 

 the principal variations found in the hepatic and cystic ducts. 



TABLE 3a 

 Ductus choledochus 



Left hepatic duct Right hepatic duct 



Lt. lat. ramus, Lt. med. ramus Rt. med. ramus, Rt. lat. ramus 



Branches — Lat., Med. Lat., Med. Med. Lat. Med. Lat. 



Cystic duct 



