224 PHYSIOLOGY AT THE FAKM. 



fine striae and dots correspond to minute pore-canals, and that 

 the absorption of fat is accomplished by its minute particles 

 being taken up through these minute pores upon the surface 

 of the epithelial cells. Another conjecture is, that the upper 

 border of the cell is composed of little rods or pillars resem- 

 bling cilia. However this may be, the fat passes through the 

 cells, so that at first only their outer end is filled with it, then 

 after a time the outer end becomes entirely free from it, the 

 inner still containing a little, and at last the fat entirely 

 vanishes from the cells. After the fat has proceeded as far as 

 the inner extremity of the cells, it begins to pass into the 

 parenchyma of the villus. In the interior of the villi there is 

 found a network of blood-vessels somewhat below the sur- 

 face, and in the axis a tolerably wide canalicular cavity with a 

 blunt extremity, which appears to be the commencement of 

 the lacteal vessel. At the periphery of the villus a layer of 

 muscular fibres has been recently announced, which must be 

 of great importance in digestion, as by their contraction the 

 apex of the villus is made to approach to its base. When the 

 villi are cut off from the intestine of an animal just killed, 

 they may be seen under the microscope to contract, become 

 wrinkled, thicker, and shorter thereby a pressure from with- 

 out inwards is manifestly produced, which promotes the on- 

 ward movement of the juices.* 



Something analogous to what has just been described takes 

 place in the liver with respect to the transitory presence of 

 fat in the hepatic cells. A sucking animal, a few hours after 

 digestion has taken place, shows the presence of a fatty liver, 

 not as a morbid condition, but as a physiological occurrence. 

 When of the same litter of animals some are allowed to suck, 

 while the rest are made to fast, those only which have sucked 



* Abridged from 'Cellular Pathology,' by Virchow, translated by 

 Chance. 



