CHAPTER XII. 



THE LYMPHATIC SYSTEM. 

 BY DR. W. R. BIRDS ALL, NEW YORK CITY. 



HISTOLOGICAL research has brought to light within recent 

 years no more important or interesting facts than those con- 

 nected with the lymphatic system ; interesting, in exhibiting 

 entirely new features in tissues which had previously been 

 carefully studied ; and important in their physiological, and, 

 particularly, in their pathological relations. 



Assisted by experimental pathology, it is still in this direc- 

 tion that we are to look for advancement in pathological his- 

 tology, for there can be no doubt that heretofore too little, 

 attention has been paid to the lymphatic system, both in its 

 histological details and in its topographical anatomy. 



Present condition of the mews on the structure of the lym- 

 phatic system Relations to the connective tissues. Unfor- 

 tunately we have still a great variety of contradictory observa- 

 tions, and various interpretations of the same observations. 

 Through this maze of uncertainties it is not easy to lead the 

 student to a settled opinion, nor can all the phases of this many- 

 sided subject be presented. It shall be our aim, however, to 

 draw the outlines. If the student wishes to follow out the 

 controversies, he will be aided by the references which are 

 appended to this chapter. 



It may be said that we have, to a great extent, returned to 

 the views of the older anatomists and physiologists, and be- 

 lieve that the whole connective- tissue formation is a network of 

 channels ; that its interstices are, directly or indirectly, con- 

 nected with the lymphatic capillaries and larger vessels ; that, 

 in short, the lymphatic system is pre-eminently a connective- 

 'tissue circulatory system, irregularly distributed, it is true, but 



