LIVER. 49 
Give the structure of the crypts of Lieberkuhn. 
They are simple, straight, tubular glands, lined with cylindrical- 
shaped cells. 
What are the solitary follicles ? 
They are little masses of lymphoid tissue placed in the mucous 
membrane of the small intestine. They sometimes extend down to 
the sub-mucous coat and are closely connected with the lymphatic 
vessels, No villi cover them. 
What is a Peyer’s patch ? 
It appears to be an aggregation of these solitary follicles arranged 
together in large, oval masses in the lower portion of the small intes- 
tine. The lymphoid tissue of which each is composed is not covered 
with villi. 
What is the structure of the mucous membrane of the large in- 
testine ? 
Tt contains numerous straight tubular glands similar to the crypts 
of Lieberkiihn in the small intestine. There are also numerous 
patches of lymphoid tissue in it similar to the solitary follicles in the 
small intestine. 
LIVER. 
What are the distinctive elements that make up the liver ? 
Connective tissue, liver-cells, and the blood, lymphatic and gall 
vessels, 
Describe the connective tissue of the liver. 
The organ is covered by a dense connective-tissue coat or capsule. 
A certain amount of this tissue is present accompanying the blood- 
vessels and is called Glisson’s capsule. Lastly, an exceedingly small 
amount is formed about the hepatic veins and between the liver cells. 
Describe the shape and arrangement of the liver cells. 
These cells, which form the parenchyma of the liver, are irregu- 
larly polyhedral in shape. They are granular and have a large, distinct 
nucleus. They are arranged in polyhedral masses or lobules. The 
cells in these lobules are arranged in single or double rows radiating 
from the centres of the lobules. In the liver of the pig the lobules 
are separated from one another and entirely surrounded by the con- 
nective tissue of Glisson’s capsule. Jn the human liver this connec- 
tive tissue is not so abundant, occurring only in patches in the spaces 
between the liver lobules. 
4—H.P.B. 
