322 FUNCTIONS OF NUTRITION. 



discharged from the thoracic duct per hour, for every thousand parts 

 of bodily weight : 



HOURLY QUANTITIES OF LYMPH AND CHYLE IN THE DOG, 



PER THOUSAND PARTS OF BODILY WEIGHT. 



3i hours after feeding 2.45 



7 " " " 2.20 



13 " . " " 0.99 



18 " " " 1.15 



18J " " " 1.99 



It would thus appear that the hourly quantity of these fluids, after 

 increasing with digestion and diminishing during its latter stages, 

 again increases somewhat about the eighteenth hour. It is probable 

 that this double increase is owing to two causes. The fluid obtained 

 in greatest abundance in the dog, from 3 to 7 hours after feeding, 

 is white and very opaque, and its quantity is largely due to the 

 admixture of chyle absorbed from the intestine. That drawn about 

 the eighteenth hour is opaline, or nearly transparent, and consists of 

 lymph alone. The absorption of chyle, therefore, takes place while 

 digestion is in progress ; but the production of lymph occurs most 

 abundantly some hours later, after the materials of nutrition have 

 reached and permeated the tissues. 



The daily quantity of lymph and chyle has been found, by direct 

 observation, much larger than would be anticipated. In two experi- 

 ments on the horse, extending over a period of twelve hours each, 

 Colin * obtained from the thoracic duct, on the average, 893 grammes 

 of fluid per hour, which, if continued for the remaining twelve hours, 

 would amount to rather more than 20 kilogrammes per day. In the 

 ruminating animals, according to the same observer, the quantity is 

 still greater. In a cow of ordinary size, the smallest amount obtained, 

 in an experiment extending over twelve hours, was 625 grammes in 

 fifteen minutes ; that is, 2500 grammes per hour, or 60 kilogrammes 

 per day. In another experiment with a young bull weighing 185 

 kilogrammes, he withdrew from the thoracic duct in twenty -four hours, 

 15 kilogrammes of lymph and chyle, representing a little more than 

 8 per cent, of the entire bodily weight. 



We have obtained similar results in the dog and the goat. In a 

 young kid weighing 6.36 kilogrammes, 122.5 grammes of lymph were 

 collected from the thoracic duct in three hours and a half. This rep- 

 resents 35 grammes per hour, and, if continued throughout the day, 

 would amount to 640 grammes, or fully 10 per cent, of the bodily 

 weight. In the dog the fluids from the thoracic duct were less abun- 

 dant ; the total daily quantity in this animal, according to the average 

 of observations at various periods after feeding, being very nearly 

 four and a half per cent, of the bodily weight. This is substan- 



Physiologie compares des Animaux domestiques. Paris, 1856, tome ii., p. 106. 



