274 



ABSORPTION LYMPH AND CHYLE. 



absorption they carry a liquid which is identical with the contents of other 

 lymphatic vessels. In their structure, also, the lacteals are identical with 

 the general lymphatics. 



Owing to the exceeding tenuity of the walls of the small lymphatics and 

 the existence of great numbers of valves which prevent injection from the 

 large trunks, the anatomy of these vessels is studied with some difficulty ; 

 and still greater difficulty is presented in the study of the vessels of origin of 

 the lymphatic system in different tissues and organs. The origin of the 

 lymphatics in the intestinal villi has already been considered, and it remains 

 to study the origin of these vessels in other parts. 



Comparatively recent investigations, particularly those of Yon Eeckling- 

 hausen and his followers, have entirely changed the views of anatomists 

 with regard to the mode of origin of the lymphatics of various parts ; but 

 the results of these investigations are so definite and positive and have been 

 so fully confirmed, that they are now almost universally adopted. Accord- 

 ing to these results, the lymphatics have several modes of origin. 



In the connective tissues, which are so widely distributed in the body, 

 there are always found, irregularly shaped, stellate spaces, which communicate 



II 



FIG. 82. Origin of lymphatics (Landois). 



I. From the central tendon of the diaphragm of the rabbit (semi-diagrammatic) : s, lymph-canals com- 



municating by x with the lymphatic vessel L ; A, origin of the lymphatic by a union of lymph- 

 canals ; E, E, endothelium. 



II. Perivascular canal. 



with each other by branching canals, that can properly be called lymph- 

 spaces, or " juice-canals." These spaces contain a liquid and large numbers 

 of leucocytes. The leucocytes in these spaces may be called lymph-corpus- 

 cles, as they eventually find their way into the true lymphatic vessels ; but 

 they are thought to be white blood-corpuscles which have passed through the 

 stomata of the capillary blood-vessels. The connective-tissue lymph-spaces, 

 by certain of their branches, finally communicate with the so-called lymph- 



