SECTION VII 
THE ALIMENTARY TRACT, PART 3. 
THE PANCREAS 
The pancreas, an organ functionating as a gland with 
an internal secretion and by pouring a digestive juice into 
the duodenum, remains a structure of constant anatomy 
throughout the zoological classes under discussion in that 
it is composed of compound racemose lobules whose 
outlets join to form large discharging ducts, and of 
interstitial bodies, the islands of Langerhans, without 
connection with the secreting acini but having some rela- 
tion with the blood and lymph vessels. The organ 
originates embryologically by sprouts from the side of 
the primitive gut just below the part destined to be 
stomach, and from an outbudding of the common biliary 
duct. These two sprouts or pouches combine to form one 
organ, but this does not necessarily effect a union between 
their lumina. In some birds and mammals (Accipitres 
and some Ungulata) the lobes of the pancreas remain 
distinct during life, and the discharging tubules seem to 
empty only their respective lobes. However, there is no 
uniformity in the matter, and indeed the anatomy of the 
ducts is subject to very great variation despite the rather 
similar beginnings of the organ. Those who are inter- 
ested in this point may consult Beddard,(l) Letulle and 
Nathan-Larrier,(2) and Opie (3) ; there will be given in 
the following pages the average findings of anatomy of 
the gland body and of its ducts. 
The region of the pancreas in lower animals, espe- 
cially those which travel constantly on four feet, is one of 
great activity, and the organs are more freely movable 
than in the human being. The only exception to the latter 
(1) Proc. Zool. Soc. London, 1905. 
(2) Bull. Soc. Anat., 1898, 73, 491 
(3) Amer. Med., 1903, 996 
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