200 The Blood-Supply of Lymphatic Vessels in Man 
The lymphatics of the serosa of the intestine are particularly interest- 
ing in man since they are so large and take up relatively so great a 
portion of its surface. Indeed when they are flattened in collapse against 
the intestine, their capillaries seem to constitute a special blood-supply 
for the serosa and it is at first easy to mistake them for that. The 
supply of these serosal lymphatics is almost always by a special set 
of capillaries which overspreads their outer surface only. Their under 
Fic. 4. Showing the blood-supply at the angle of junction of two serosal 
lymphatics. X 40. 
surface is supplied by the capillaries of the longitudinal muscle layer, 
with which they are in contact. Long slender arteries and veins, usually 
from the submucosa, penetrating the muscle coats, which they supply, 
reach the serosa and course there with the lymphatic channels. From 
these vessels, often in beautiful regularity, arteriole and venule alternately 
supply and drain the capillary plexus which is thrown over the lymphatic’s 
outer surface. We may call one of these arterioles, with its corresponding 
