552 Franklin P. Johnson. 
the bases of the villi and extend into the mesenchyma. This 
view was later accepted by Hilton (’02). 
So far as can be observed from sections, the results of the present 
work are in accord with those of Voigt and Hilton. In a wax 
reconstruction of the intestinal epithelium at 837 mm. (not figured) 
no evidences could be seen of the glands from an external view of 
the epithelium. At 55 mm. (fig. 22) the exterior of the epithelium 
in the mid region of the small intestine shows small knoblike out- 
growths. These I have considered to be the very first appearances 
of the intestinal glands. The cells of these knoblike processes are 
very granular, distinctly different from the clearer cells on the 
tops and sides of the villt. In amongst the granular cells can be 
seen a few scattered goblet or beaker cells. The protoplasm of 
the goblet cells is clear, their flattened or crescentic nuclei staining 
deeply. In the duodenum of this stage (55 mm.), the beginning 
glands are somewhat more pronounced. In embryos of 73 mm., 
91 mm., and 120 mm., the glands gradually become more distinct 
and longer, and the goblet cells which line both the glands and the 
villi become more numerous. The intestinal glands at 134 mm. 
(mid region of the small intestine) are shown in fig. 23, and at 240 
mm. (duodenum) in fig. 24. Throughout the older stages, the 
glands increase in length andin number. They are usually simple 
tubular in form, but some are branched. Measurements of the 
glands in different stages of development are given in Tables3 
and 4. 
Duodenal Glands. Regarding duodenal (Brunner’s) glands 
Koelliker states that their formation begins in the fourth month 
and that they are originally the Lieberkiihn glands. Later they 
send branches into the submucosa, which, at the end of the sixth 
month, reach to the muscular layer. Barth found that in the 
rabbit the duodenal glands sprout off from the Lieberkiihn glands 
as a double outgrowth. Brand (’77) observed Brunner’s glands 
first in a human embryo of three and one half months. 
In the duodenum of an embryo of 55 mm. no traces of the duo- 
denal glands could be found, while at 78 mm. (Embryo 142)— 
three months—a few could be seen in the upper third of the duo- 
denum. They arise from the bottoms of the intestinal glands, 
