CHARACTERS OF LYMPH AND CHYLE. 205 



On their way to enter into the blood-current both the lymph 

 and chyle undergo certain changes. Before passing through the 

 lymphatic glands the fluid contains much fewer lymph corpuscles 

 than after it has traversed the glands : from this fact and from 

 the structure of the lymph glands we may conclude that they are 

 the chief sources of these white cells. The chyle of the lacteal 

 vessel of the mesentery contains particles of fat which greatly ex- 

 ceed in size those found in the thoracic duct, so we may infer that 

 the fat emulsion undergoes a further subdivision or modification 

 on its way through the glands. 



The lymph which has been collected from the lymph channels 

 of the extremities has been found to contain less albumin than 

 that coming from the main trunk, and after long fasting the 

 lymph from the thoracic duct has the same characters. 



The lymph contains a considerable quantity of carbonic acid 

 gas, about 50 vol. per cent., some of which is readily removed 

 by the air-pump, and is therefore said to be merely absorbed by 

 the fluid, and some of which can only be removed by the addi- 

 tion of acids, and is therefore considered to be in chemical com- 

 bination. Only mere traces of oxygen have been found in the 

 lymph. 



The quantity of chyle and lymph poured into the blood varies 

 so much that any estimation of the amount entering in a given 

 time is unreliable. 



The following circumstances upon which the variations may 

 depend are instructive : 



1. The iugestiou of liquid and solid food causes a great in- 



crease in the amount of chyle. This is obvious from 

 the change in the state of the lacteal vessels, which 

 from being transparent and almost empty become 

 widely distended and white. 



2. The activity of any organ causes an increase of lymph to 



flow from it. 



3. Impediment to the return of the venous blood from any 



part increases the irrigation, i.e., the lymph. 



