LACTEAL ABSORPTION. 131 



absorption. What gives countenance to this idea is the acid 

 reaction discoverable in the caecum. But, as respects the ox 

 at least, this view has not as yet attained any firm ground of 

 belief. The mass, deprived of its nutritive constituents, and 

 mingled with the residue of the bile, of the pancreatic juice, 

 and of the intestinal secretions, is transmitted to the great 

 intestines, and finally thrown forth from the rectum. 



Lacteals. The lacteals commence in the villi of the intes- 

 tines ; they form a close plexus, and proceed to the thoracic 

 duct in which they all terminate. They are derived much 

 more numerously from the small intestines than from the 

 large intestines. Whence their chief seat is the mesentery, 

 and particularly that part of it which upholds the jejunum 

 and the ilium. As the transverse colon in the ox is con- 

 tained in the upper part of the mesentery, it is less easy in 

 the ox than in many other animals to distinguish between the 

 few lacteals passing from the great intestine and the great 

 number passing from the small intestine. Two sets of absorb- 

 ent vessels are met with along the intestinal tube, each of 

 which has a different position and direction. The set which 

 lies nearest to the external surface of the gut runs along the 

 canal longitudinally, immediately beneath the peritoneal coat ; 

 while the other set, lying deeper between the muscular and 

 mucous coat, turns transversely around the intestine, and 

 thence proceeds, along with the arteries and veins, between 

 the two laminae of peritoneum which form the mesentery. 

 The distinction formerly made between those two sets of 

 absorbents namely, that the superficial set were lymphatics, 

 and the deep-seated set alone lacteals does not hold good. 

 They communicate freely by anastomosis. What was said 

 long ago by a high authority is true namely, that the lacteals 

 absorb chyle when it is presented to them ; at other times they 

 absorb other fluids. These absorbents run through the mesen- 



