510 Intestinal Diverticula in Embryos of the Pig, Rabbit, and Man 
The occurrence of diverticula in the 24 pig embryos already described 
may be tabulated as follows: 
Bares Length. Diverticula. ae Length. Diverticula. 
915 5.5 mm. 1 518 12.0 mm. 1 
916 5.5 mm. 2 65 14.0 mm. 3+1 detached 
918 6.0 mm. 1 66 14.0 mm. 3 
919 6.0 mm. 1 1130 14.0 mm. 1-+ 2 detached 
9 6.0 mm. 2 51 UA saahon, 8) 
11 7.0 mm. 2 50 17.0 mm. 10+ 1 detached 
428 7.8 mm. 1 very small 59 20.0 mm. 11 
29 7.8 mm. 3 60 20.0 mm. 20 
52 9.0 mm. 2 61 20.0 mm. 12 + 1 detached 
414 10.0 mm. 1 very small 62 24.0 mm. 14 
402 10.0 mm. 0 64 24.0 mm. 15 
5 12.0 mm. 1+ 1 detached 136 32.0 mm. present. 
Summary.—tn pig embryos from 5.5 to 14 mm. in length, one or two 
knob-like diverticula occur regularly in the duodenal region. Sometimes 
they are small as in Series 428 and 414, or absent as in Series 402, but 
usually they are easily found. In embryos from 14 to 24 mm. the num- 
ber of diverticula increases and they are distributed along the small intes- 
tine. None were found in the large intestine, except in the 32-mm. 
specimen, where a cluster of diverticula occurred near the ileum. The 
diverticula appear first in the duodenum, and later in the lower portion 
of the small intestine. They begin as round knobs which may become 
elongated and detached from the intestine in the form of nodules, strands 
or cysts. In later stages they acquire a lumen and those found in the 
distal part of the small intestine appear as flask-shaped gland-like 
pockets. 
RABBIT EMBRYOS. 
At 11 and 113 days, rabbit embryos contain both the dorsal and the 
ventral pancreas, but no intestinal diverticula. This is true of some at 
12 days, but Series 147, of a 5-mm. rabbit of 12 days, shows a pearl-like 
disturbance of the epithelial cells, suggestive of the later pockets. At 13 
days (H. E. C. 153, 7.5 mm.) a round pocket with a lumen emptying 
into the intestine occurs just beyond the duct of the dorsal pancreas. 
The pocket is 0.07 mm. in diameter and extends through six sections. 
In this embryo there are also three pearls along the anterior limb of the 
intestinal loop. 
At 14 days (H. E. C. 156, 10.5 mm.) there is a duodenal pocket, near 
which a detached epithelial nodule, containing a lumen, appears in three 
