THE LYMPHATIC SYSTEM. 323 



tially the same result as that obtained by Colin in the horse; and 

 for a man weighing 65 kilogrammes, it would be equivalent to about 

 3000 grammes of lymph and chyle per day. This represents both the 

 products of lymphatic transudation and those of intestinal absorption. 

 An estimate of the lymph alone must be based upon the quantity of 

 fluids passing through the thoracic duct in the intervals of digestion, 

 when no chyle is absorbed from the intestine. In the dog, the aver- 

 age quantity obtained, from the thirteenth to the nineteenth hour 

 after feeding, was about 1.30 per thousand parts of the bodily weight ; 

 or, for the whole twenty-four hours, a little over 3 per cent, of the 

 bodily weight. For a man of medium size, this would give not far 

 from 2000 grammes as the average daily quantity of lymph alone. 



Internal Renovation of the Animal Fluids. The combined opera- 

 tion of secretion, transudation, and reabsorption produces a continual 

 interchange of the animal fluids, which is dependent for its materials 

 upon the blood, and which may be considered as a kind of secondary 

 circulation through the substance of the tissues. All the fluids dis- 

 charged into the small intestine are reabsorbed and again enter the 

 current of the circulation. They pass and repass through the mucous 

 membrane of the alimentary canal and adjacent glands, becoming more 

 or less altered, but still serving to renovate alternately the blood and 

 the secretions. The elements of the blood transude in part from the 

 capillary vessels, and are taken up from the tissues by the lymphatics, 

 to be again restored to the circulation at its venous extremity. 



The quantity of fluids thus transuded and reabsorbed will serve to 

 indicate the activity of endosmosis and exosmosis in the living body. 

 In the following table, the amounts are estimated, from the preceding 

 data, for a man of average size : 



FLUIDS TRANSUDED AND REABSORBED DURING TWENTY-FOUR HOURS. 



Saliva 1280 grammes. 



Gastric juice 3000 " 



Pancreatic juice 800 " 



Bile 1000 " 



Lympli 2000 a 



8080 " 



Not less than 8000 grammes therefore of the animal fluids, a quantity 

 equal to that of the entire blood and amounting to more than 12 per 

 cent, of the bodily weight, transude through the membranes and are 

 restored to the blood by reabsorption, in the course of a day. By this 

 process the natural constitution of the parts, though constantly changing, 

 is maintained in its normal condition, through the movement and reno- 

 vation of the circulating fluids. 



