Fred W. Thyng 495 
ably, as both have found cases in the adult rabbit where the supposed 
ventral pancreas was entirely free from the dorsal. 
In the 11 mm. embryo, a part of the dorsal pancreas beyond the place 
of anastomosis is represented only by a small strand which passes on the 
left of the portal vein, and connects with the main portion of the dorsal 
pancreas (‘Panc. d.), which lies in the mesogastrium. 
Thus the portal vein in the rabbit as in the pig is surrounded by a ring 
of pancreatic tissue, as was observed by Brachet and Helly. 
The pancreas in the adult rabbit has been investigated by Bernard, 56, 
Schirmer, 93, Joubin, 95, Brachet, 96, and others. The duct of the 
dorsal pancreas occurs regularly. Bernard and Joubin found several 
cases where both ducts were present; Schirmer found 7 cases out of the 
22 specimens examined, where both occurred; and Brachet believes that 
both ducts generally persist. 
Cat EMBRYOS. 
Felix, 92, was the first to study the pancreas in the embryo cat. In the 
adult he knew of only one pancreatic duct, that of the ventral pancreas. 
In his oldest cat embryo (11 mm.), he thought that the dorsal pancreas 
was degenerating, hence he concluded that only the ventral pancreas is 
represented in the adult. 
Hammar, 93, in connection with his work upon the development of 
the liver, figures a model from a cat embryo 5 mm. long (Fig. 5, Taf. 
XI). It shows the dorsal pancreas arising from the dorsal wall of the 
intestine nearly opposite the opening of the common bile duct. 
Helly, or, demonstrated the error of Felix’s conclusion, since he found 
in an embryo of 10 mm. that the dorsal pancreas was much larger than 
the ventral, and showed no trace of degeneration. 
The model which I am about to describe is from an embryo 10.7 mm. 
in length (H. E. C. 474). It is represented (Fig. 3) somewhat ventrally 
from the right. The stomach (S¢.) has swung over to the left side of 
the embryo, its pyloric end now extending toward the right. The duo- 
denum, proceeding from the pylorus, extends also toward the right and 
anteriorly, crosses the median line, then bending posteriorly, descends 
for some distance. Near this bend the bile duct (D. chol.) enters the 
intestine. 
The ventral pancreas (Pane. v.), situated in the lesser omentum, is 
considerably smaller than the dorsal outgrowth. It is entirely free from 
the latter, although the two are in close proximity ventral to the portal 
