154 



ANIMAL PHYSIOLOGY. 



116. The fluid taken up by the lacteals from the contents of 

 the intestine is termed chyle. The chyle resembles lymph in 

 containing albumen and salts, and in not containing nucleated 

 corpuscles, nor being spontaneously coagulable, until it has 

 passed through lymphatic glands ; but it is distinguished by 

 its milky appearance. This milkiness varies according to 

 the nature of the diet, the greatest opacity and whiteness 

 occurring when the food is rich in oleaginous constituents; 

 and on microscopic examination it is seen to depend on the 

 presence of multitudes of exceedingly minute molecules of 

 oil, which, floating, as they do, in an albuminous fluid, have 

 no tendency to run together into larger globules. The term 

 chyle is sometimes applied not only to the milky contents of 

 the lacteals, but also to the emulsion contained in the intes- 

 tine below the entrance of the pan- 

 creatic duct, which is the source from 

 which the lacteals are filled; and a 

 sharp distinction is thus drawn 

 between the chyme or pulp formed 

 by the action of the stomach, and 

 the material lower in the intestine. 

 This extended use of the term chyle 

 is, however, objectionable, as the 

 two fluids to which it is applied are 

 not identical; that which is found 

 in the intestine containing not merely 

 what is fitted to be taken into the 

 lacteals, but large quantities of other 

 matters, partly destined to be ab- 

 sorbed by the capillary blood-vessels, 

 Firr, 81. Two VILLI of anc ^ P ar %" to pass onwards and under- 

 human intestine de- go further change, or be ejected, 

 prived of their epi- 117. The nourishment prepared 

 thelium, and with the j n the alimentary canal is taken up, 



B a eL te SecTed. b The'Ia e :: P^7 *** *" blood-vessels, and 



teals are white, the partly into the absorbents; and al- 



blood - vessels black though this process undoubtedly may 



(Teichmann). , & g on ^ o some extent in the stomach 



and whole length of the intestinal tract, it is carried on 



most actively by the villi of the small intestine (p. 99). 



