72 
pancreas. A lumen is not generally apparent, but the 
presence of such is generally associated with a particular 
phase of the activity of the gland which doubtless did not 
coincide with the fixation of our material of the organ. 
They are small and in a single transverse section are 
composed of few polygonal cells. 
Not only does the pancreatic tissue form a peri- 
vascular investment in the vessels in the body cavity, but 
it extends along the portal veins into the interior of the 
liver. Text-fig. 1, A. represents a section of a part of the 
latter organ, and shews a small portal vein cut in trans- 
verse section with two veinules opening out from it and 
passing between the hepatic cells. A single layer of 
pancreatic gland acini forms an investment for the vessel, 
and the whole les within a space in the hepatic tissue 
which is probably natural. The acini are elongated per- 
pendicularly to the surface of the vessel, and the whole is 
surrounded by a fibrous sheath which sends in partitions 
between the acini, becoming continuous with the fibrous 
wall of the vein. Here also a lumen is generally wanting, 
or is only with difficulty apparent in the acini. 
In Acipenser, Amia and Lepidosteus Macallum* has 
described very similar relations for the pancreas, and the 
description of the organ given by Gullandt for Salmo 
answers in all essential respects to that stated above. 
Macallum} has described the pancreas in Améurus as being 
imbedded in the liver round the interlobular veins. The 
diffuse condition of the pancreas seems to be characteristic 
of most Teleostomatous fishes hitherto investigated, and is 
most probably quite general. 
* Loc. cit. 
| Life history of the Salmon; Rep. to the Fishery Board of Scotland, 1898. 
} Proc. Canadian Institute, N.S. vol. ii., No. 3, pp. 387-417, 1884. 
