512 Intestinal Diverticula in Embryos of the Pig, Rabbit, and Man 
one pocket. The duodenal diverticulum in one of these is shown in the 
reconstruction Fig. 3 on p. 494 of the preceding article; a section through 
it is seen in Fig. 3 C. As in the pig, mitotic figures are not limited to 
the diverticula. 
Human Empsryos. 
An embryo of 4.0 mm. (H. E. C. 714) has previously been described 
by Dr. Bremer* as presenting two solid epithelial knobs on the mid- 
ventral border of the intestinal tube. One of these is just beyond the 
hepatic diverticulum; the other is nine sections further on, at the place 
where the intestine begins to expand to form the yolk sac. The second 
Fig. 5. Reconstruction from a human embryo of 13.6 mm. (H. E. C. 839). 
x 55 diams. Div., diverticulum. WD. chol., ductus choledochus. D. cyst., 
ductus cysticus. D. hep., ductus hepaticus. D. panc. d., ductus pancreatis 
dorsalis. Panc. d., pancreas dorsale. St., stomach. 
knob, which is seen in two sections, is in contact with the intestinal epi- 
thelium, but. is, apparently detached. The dorsal pancreas has not 
appeared. 
In five much older embryos, measuring from 7.5 to 10.2 mm., no 
diverticula were found. In an embryo which in alcohol measured 13.6 
mm. (H. E. C. 839), there is a well developed duodenal pocket shown in 
the reconstruction (Fig. 5) and in the section (Fig. 3 B). Above this 
diverticulum the lumen of the duodenum is subdivided into two or three 
parts by the proliferation of the epithelium. Such proliferation, which 
* Bremer, J. L. Description of a 4-mm. human embryo. Amer. Journ. of 
Anat., 1906, Vol. 5, p. 459-480. 
