460 PHYSIOLOGY OF THE DOMESTIC ANIMALS. 



transparent, and of yellowish or reddish tint. In suckling herbivora, 

 as in the carnivora, it is milky. 



In its passage from the intestine to the thoracic duct it undergoes 

 important changes in composition. At first it contains albumen in solu- 

 tion, oil-globules in suspension, and is not spontaneously coagulable. 

 After it passes through the mesenteric lymphatic glands lymph-cor- 

 puscles are added, and it acquires the property of undergoing fibrinous 

 coagulation. It becomes poorer in albumen and fats in its onward 

 progress, and richer in corpuscles and fibrin. 



When taken from the thoracic duct after a full meal of fat it is a 

 white, milky-looking fluid, which undergoes spontaneous coagulation on 

 exposure to the air. The nature of the coagulation of the chyle is iden- 

 tical with that of the blood, to be subsequently studied, and is due to 

 the addition in the mesenteric glands of immature blood-corpuscles and 

 fibrin factors. 



Examined under the microscope, the coagulated chyle obtained from 

 the thoracic duct contains fibrin, a large number of white blood- or 

 lymph-corpuscles, a few immature red blood-cells, oil-globules inclosed iii 

 albuminous envelopes, and fatty granules. 



The composition of chyle differs in different animals and at dif- 

 ferent periods in the same animal, dependent on the rapidity and nature 

 of absorption taking place from the intestinal surface. In the chyle 

 obtained from horses fed with ha}- the fat scarcely exceeds in amount 

 that found in the blood, at most not more than 1 per cent., while it may 

 rise to 3.10 per cent, in horses fed with oats. It is made up of formed 

 elements (lymph-corpuscles added as the chyle passes through the 

 mesenteric lymphatics) suspended in a fluid medium (serum). 



The serum contains the following bodies in solution in water : — 



1. Globulin, alkali albuminate, serum-albumen, and peptones in 

 small amount, rising during digestion to 0.6-0.7 per cent. 



2. Cholesterin, lecithin, and fatty soaps. 



3. Dextrose, varying from a mere trace to 2 per cent., depending on 

 the amount of carbohydrates in the food. 



4. Urea derived from the lymph, and alkaline lactates, especially in 

 the herbivora, and after starchy food. 



5. Inorganic salts of the alkalies and alkaline earths, iron, phos- 

 phoric acid, etc. (Charles). 



As a result of sixteen analyses of the chyle of the horse, Gorup- 

 Besanez gives the following figures : — 



Water 871.0 to 967.9 in 1000 parts. 



Albumen 19.32" 60 53 



Fat, traces " 36.01 



The chyle possesses the power of converting starch into sugar, 



