514 Intestinal Diverticula in Embryos of the Pig, Rabbit, and Man 
SIGNIFICANCE OF THE DIVERTICULA. 
Volker * has interpreted a slightly elongated diverticulum in a pig 
embryo as an accessory pancreas. The length of the embryo is not stated, 
but the reconstruction of it agrees closely with Fig. 1. Volker describes 
it as follows: 
In this embryo I have made a very interesting discovery, namely that a 
new accessory pancreas arises from the lumen of the intestine almost in the 
mid-ventral line and in about the third section beyond the connection of the 
pancreas with the intestine; it can be followed distally for about four sec- 
tions. It consists of polyhedral cells of exactly the same character as those 
in the rest of the pancreas, but it has no lumen. In spite of the most careful 
investigation I could not demonstrate a similar structure in any other 
embryo. It is probably to be regarded as an individual variation. 
Thyng, in the preceding article in this journal, likewise interprets an 
elongated diverticulum in the pig embryo of 20 mm. as an accessory 
pancreas. Bremer regards the mid-ventral epithelial knobs in the 4 mm. 
human embryo as pancreatic, although anomalous in position and time 
of development.’ 
The conditions in the lower vertebrates do not account for a series of 
pancreatic outgrowths. Cyclostomes and selachians are said to have only 
a dorsal pancreas; teleosts, amphibians and higher groups have one 
dorsal and one ventral pancreas, the lateral lobes of the latter often being 
counted as two. In the sturgeon, however, yon Kupffer* has described 
and figured a third outgrowth—a median dorsal structure posterior to 
the others. A portion of it is thought to give rise to the spleen, but the 
remainder fuses with the other two outgrowths to make the pancreas of 
the adult. Stohr’ has denied the correctness of these observations, and, 
although reaffirmed by von Kupffer, they lack confirmation. 
It is well known that a small pancreas may develop at various places 
along the human small intestine. Through the kindness of Dr. James 
H. Wright we have examined sections from four such cases—one from 
*Volker, O. Beitriége zur Entwickelung des Pankreas bei den Amnioten. 
Arch. f. mikr. Anat., 1902, Vol. 59, p. 62-93. 
*Bremer, J. L. Description of a 4-mm. human embryo. Amer. Journ. of 
Anat., 1906, Vol. 5, p. 474. 
®von Kupffer, C. Ueber die Entwicklung von Milz und Pankreas. Miin- 
chener med. Abh., 1892, VII Reihe, 4 Heft, 17 pp. 
‘Stohr, P. Ueber Entwickelung von Hypochorda und Pankreas bei Rana. 
Verh. d. anat. Gesellsch., $th Versammlung, 1895, p. 176-179. 
® See the discussion of Professor St6hr’s paper to which reference has just 
been made. 
