LYMPHATICS. 



223 



But after digestion of fatty matter they are rilled with the 

 white Chyle, and are easily seen. 



To show the thoracic duct, feed a kitten or puppy on rich 

 milk, and after two or three hours kill it as directed on page 

 67. As soon as you are sure it is dead, open the abdominal 

 cavity, and spread out the mesentery. The white lacteals, 

 filled with chyle, will be seen radiating through the mesentery. 

 Press on some of these, and it will be seen that they are thin 

 tubes filled with a white liquid. They converge toward the 

 place of attachment of the mesentery to the dorsal part of the 

 abdomen. On the dorsal wall of the abdomen, just posterior 

 to the diaphragm, the Receptacle of the Chyle, or the beginning 

 of the main lymph vein (thoracic duct), should be found. 

 Trace it anteriorly through the chest alongside the aorta to 



Lacteal with Valves Capillaries Muscles Epithelium 



Fig. 67. Elements Entering into the Structure of a Villus. 



its mouth, near the junction of the left subclavian and jugular 

 veins. 



The thoracic duct may be injected, though it is not always 

 easy to do so. Use a small syringe and the starch preparation 

 described on page 66. After finding the receptacle of the 

 chyle, snip a small hole in its posterior end, and quickly 



