462 ABSOEPTION. 



a feebly alkaline fluid. The membrane used was the urinary 

 bladder of the ox, and the temperature was 80 Fahr. at the 

 beginning of the experiment. In a very short time, the 

 liquid had mounted in the endosmometer more than an inch. 1 

 In these experiments, the liquids were not more strongly al- 

 kaline than the blood or the lymph ; and it is fair to infer 

 that in the intestine, where the conditions are as favorable 

 for absorption as possible, the minute fatty pajticles of the 

 chyle can pass through the coats of the lacteals or the .blood- 

 vessels to the lymph and the blood, which fluids are always 

 distinctly alkaline. Though we cannot at present explain 

 precisely how emulsions pass through membranes in which 

 no orifices can be demonstrated, the fact of their penetration 

 can hardly be doubted. 



In studying the mechanism of the penetration of fatty 

 particles into the intestinal villi, it has been ascertained that 

 the epithelial cells covering the villi play an important part 

 in this process. It was first ascertained by Goodsir that 

 during the digestion of fat these cells became filled with fatty 

 granules. 2 This fact has been confirmed by Gruby and 

 Delafond, 3 Kolliker, 4 and others. Prof. Dalton, in his work 

 on physiology, figures the appearances of the intestinal 



1 MATTEUCCI, Lecons sur les Phenomenes Physiques des Corps Vivants, Paris, 

 1847, p. 105. 



2 GOODSIR, On the Structure of the Intestinal Villi in Han and certain of the 

 Mammalia, with some Observations on Digestion, and the Absorption of Chyle. 

 The Edinburgh New PhilosophicalJournal, 1842, vol. xxxiii., p. 167. Goodsir 

 thought that the epithelium of the villi was for the protection of these parts 

 during the intervals of digestion, and that the cells were always desquamated dur- 

 ing absorption ; but this view is not now entertained. 



3 GRUBY ET DELAFOND, Resultats des Recherches faites sur V Anatomic et les 

 Fonctions des Villosites Intestinales, V Absorption, la Preparation et la Composition 

 organique du Chyle dans les Animauz. Comptes Rendus, Paris, 1843, tome xvi., 

 p. 1194. These authors pointed out the differences between the epithelial cells 

 during fasting and during digestion ; but they made several errors in their ob- 

 servations, and described openings and ciliae on the free ends of the epithelium. 



4 KOLLIKER, Manual of Human Microscopic Anatomy, London, 1860, p. 

 329. 



