Frederic T. Lewis and Fred W. Thyng 519 
he has found diverticula, sometimes solid and sometimes glandular, which 
are regenerative centers. He states that in Melolontha vulgaris “ we find 
structures such as we have learned to recognize in Triton.” 
Nicolas * has verified the occurrence of knobs along the intestinal epi- 
thehum of Salamandra. He found mitotic figures and the three sorts 
of cells described by Bizzozero, and states that the buds occur over the 
whole extent of the small intestine and rectum. He disagrees with 
Struiken, who has said that these structures are not found in the rectum 
of the salamander, but admits that there they are much less developed 
and approach the larval form. He believes that during the winter, when 
intestinal activity is at a minimum, the buds are relatively rare. 
CONCLUSIONS. 
Knob-like intestinal diverticula occur regularly in embryos of the pig, 
rabbit, and man. Their presence is noted also in the cat and sheep. 
Similar diverticula are found along the cystic and bile ducts. These 
may give rise to glandular tissue (hepatic or pancreatic); they may 
degenerate and disappear, sometimes after becoming detached in the form 
of epithelial nodules or cysts; or they may possibly form permanent 
diverticula of the gall bladder. 
The knob-like intestinal diverticula are the probable source of an 
occasional accessory pancreas. They usually degenerate, sometimes form- 
ing detached cysts and nodules. 
The diverticula are more numerous in the older embryos studied, and 
oecur especially in the distal part of the small intestine. Although none 
were found in the large intestine, except near the valve of the colon in 
the oldest pig examined, it is possible that they may appear there in later 
stages. 
The distal diverticula probably correspond with the “ flask-shaped 
glands” (Klein) or “primary submucous glands” (Stohr), which be- 
come surrounded by lymphoid tissue and nodules. In this they resemble 
various other epithelial pockets. e 
It is possible that these structures may give rise to pathological 
“ diverticula.” 
The diverticula, although they are not exclusive centers of cell divi- 
sion, are comparable with the knob-like proliferations of the intestinal 
epithelium in the tailed amphibia, as described by Bizzozero and Nicolas. 
Nicolas, A. Les bourgeons germinatifs dans lVintestin de la larve de 
salamandre. Bibliogr. Anat., 1894, Vol. II, p. 37-42. 
