THE PRODUCTION AND ABSORPTION OF LYMPH. 



By ERNEST H. STARLING. 



CONTENTS. Tlie Production of Lymph, p. 285 The Physical Forces concerned in 

 the Movement of Lymph, p. 299 The Absorption of Lymph from the Con- 

 nective Tissues, p. 302 On the Functions of the Lymph in the Nutrition of 

 the Tissues, p. 310. 



THE PRODUCTION OF LYMPH. 



THE spleen is the only part of the body where the blood comes in actual 

 contact with the living cells of the tissue. In all other parts of the 

 body the blood flows in capillaries with definite walls consisting of a 

 single layer of cells, and is thus separated from the tissue elements by 

 these walls and by a varying thickness of tissue. All the interstices of 

 the tissues are filled with a fluid, lymph, 1 which thus acts as an inter- 

 mediary between blood and tissues. The tissue spaces, which are filled 

 with lymph, are always found in association with connective tissue. 

 They have an incomplete lining of endothelial cells, and are connected 

 with definite channels, lymphatics, by which any excess of fluid in the 

 part is drained off. The lymphatics all run towards the chest, where 

 those from the lower limbs as well as from the viscera join to form 

 a large vessel, the receptaculum chyli, which is continued into the 

 chest as the thoracic duct. This runs on the left side of the oeso- 

 phagus, to open into the large veins at the junction of the left internal 

 jugular with the subclavian vein. A small vessel on the right side 

 drains the lymph from the right upper extremity and side of the 

 chest. 



Lymph may be collected for examination by placing a cannula in 

 one of the main lymphatics of a limb, and inducing a flow by move- 

 ments of kneading and massage, from the lymphatic duct of the neck, or 

 from the thoracic duct. Since, moreover, the serous cavities of the pleura, 

 peritoneum, pericardium, and tunica vaginalis are in free communication 

 with the lymphatic system, any fluid which is normally found in them 

 may be looked upon as lymph. The various analyses of lymph that 

 have been made, show that its composition may vary considerably 

 according to the locality from which it is derived and the circumstances 

 under which it is obtained. Certain general characteristics are, how- 

 ever, common to all specimens of lymph. It is always slightly alkaline, 

 and clots spontaneously at a variable time after it has left the vessels, 



1 Adler and Meltzer (Journ. Exper. Med., Baltimore, 1896, vol. i. No. 3) draw a sharp 

 distinction between the interstitial fluid of the tissue spaces, and the lymph obtained from 

 the lymphatics which drain these spaces. 



