324 THE DEVELOPMENT OF THE CHICK 
has correspondingly in the adult three separate ducts opening 
into the duodenum. (Two pancreatic ducts is the rule in Gallus, 
according to Gadow in Bronn’s Thierreich.) Of the three pan- 
creatic diverticula, the dorsal one arises first (about 72 hours) 
then the right ventral slightly earlier than the left ventral 
(about 96 hours). The two latter arise from the common 
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Fic. 188. — Transverse section through the duodenum and hepato- 
pancreatic ducts of a chick embryo of 5 days. (After Choronschitzky.) 
Ao., Aorta. cav. F., Caval fold. Coel., Coelome. D. hep. 2, 2a, 
2b, Posterior hepatic diverticulum and branches of same. Du., Du- 
odenum. Li., Substance of liver. M/’st., Dorsal mesentery. Pa. d., 
Dorsal pancreas. Pa. v. d., Right ventral pancreas. Pa. v. s., Left 
ventral pancreas. Spl., Spleen. V. e. p., Posteardinal vein.  V. I.., 
Vena lienalis. V.o.m.d., Right omphalomesenteric vein. V.o.m.s., 
Left omphalomesenteric vein. 
hepatie diverticulum near its Junction with the duodenum (Fig. 
ISS). The differentiation of the three parts is essentially similar, 
and proceeds naturally in the order of their origin. Solid buds 
arise from the ends of the diverticula, and these branch repeatedly 
in the surrounding mesenchyme, but do not anastomose; the 
