Fred W. Thyng 497 
HumMAN Embryos. 
The pancreas was first studied in man. Wirsung, 1642-43, is consid- 
ered the discoverer of the duct which opens into the intestine by way of 
the bile duct. 
Vesling, 1664, De Graaf, 1671, and several other investigators of that 
time, noted the occasional presence of a second pancreatic duct which 
they considered abnormal. 
Santorini, 1775, and Bernard, 56, believed in the normal presence of 
two pancreatic ducts. 
In 85, His published reconstructions of human embryos, showing 
the dorsal but not the ventral pancreas. 
Phisalix, 88, was the first to explain embryologically the presence of 
two pancreatic ducts. In a human embryo of 10 mm., he found that the 
pancreas developed from two separate parts. One part corresponded 
with the “ conduit accessoire,” and developed from the duodenum a little 
above the common bile duct. The other, of smaller dimensions, corre- 
sponded with the “canal de Wirsung,” and was in intimate relations 
with the bile duct. 
Zimmermann, 8g, investigated a human embryo of 7 mm., and de- 
scribed a double ventral pancreas, arising from the bile duct. 
Felix, 92, figured the pancreas in a human embryo of 8 mm. 
(Fig. 18, Taf. XVII). He pictures a dorsal pancreas arising from the 
intestine anterior to the bile duct. The ventral pancreas is double, the 
left part being rudimentary. 
Hamburger, 92, figures models of the pancreas in human embryos of 
five and six weeks (Fig. 2 u. 3). In both, the duct of the dorsal pan- 
creas enters the intestine nearer the stomach than the bile duct. Ham- 
burger found, in an embryo of four weeks, that the ventral pancreas arose 
from the intestinal wall some distance below the bile duct. He concluded, 
therefore, that it secondarily became connected with the latter. 
Janosik, 95, represents in Figs. 18 and 20 the pancreas in human em- 
bryos of 1 and 2.9 em. In the younger embryo the opening of the com- 
mon bile duct is nearer the stomach than that of the dorsal pancreas. In 
the older embryo the relation is reversed. 
Jankelowitz, 95, studied the pancreas in a human embryo of 4.9 mm., 
and describes a dorsal and a ventral pancreas, the latter composed of 
right and left divisions. 
Swaen, 97, described the pancreas as found in embryos of 10 mm., 18 
mm., 15 mm. (nuchal length), and 4.5 em. His model of the pancreas 
