S. YOSCHIDA 217 
(IV) The Duodenal Glands of the Rat- 
The histological structure of the Duodenal glands is very simple. They 
cannot be distinguished from the pylorus glands. The tall cylindrical cells 
of which the gland walls are composed are uniform and take regular epithelial 
arrangement, supported upon the basement membrane. The Duodenal glands 
open between the villi, at the basal part of them. Abundant occurrence 
of the Goblet cells in the mucous epithelium of the Duodenal marks off this 
section of the alimentary canal from the Pylorus, where no trace of this class 
of the epithelial components is met with. 
The duodenal glands are lost from sight at the opening of the bile-duct. 
As to the structure of the Duodenal glands of rats there are two points 
which perhaps need special mentioning ; the Duodenal glands in the rat show 
in the first place every graduation of the morphological transition to the 
pyloric glands, so that the Duodenum and pylorus present no sharp demarca- 
tion in this respect, whereas we see, in the rat, a sudden change in the passing 
from one of these parts to the other. This striking feature in the alimenta- 
ry canal of therat is, in the second place, attributable chiefly to repeated 
ramification of those Duodenal glands lying close to the Pylorus ; on the other 
hand, in the rabbit this suddenly increased ramification of the glands is not 
the case, as the glands are almost equally ramified throughout the whole 
extent of their occurrence, being neither suddenly decreased in their number, 
though this is the case in the rat's Duodenum. 
