CHYLOSIS. 649 



upon, its contractile power, which may enable the particles to be 

 received within the vessel, after they have been directed towards it. 

 This contractile power may be presumed to consist in an alternation of 

 contraction and relaxation, such as is supposed to belong to all vessels 

 that are intended for the propulsion of fluids, and which the absorbents 

 would seem to possess in an eminent degree." This is specious; but it 

 would be not the less hypothetical if the chyliferous vessels had open 

 mouths, and we have seen they have not. 



By other physiologists, absorption is presumed to be effected by 

 virtue of the peculiar sensibility or insensible organic contractility or 

 irritability of the mouths [?] of the absorbents ; but these terms, as M. 

 Magendie 1 has remarked, are the mere expression of our ignorance, 

 regarding the nature of the phenomenon. The separation of the 

 chyle is, doubtless, a chemical process; seeing that there must be both 

 an action of decomposition and recomposition ; but it is not regulated 

 solely by the same laws as those that govern inorganic chemistry. 



Professor Goodsir, 2 with almost all modern physiologists, has referred 

 the function to the agency of cells. Having fed a dog with oatmeal, 

 butter, and milk, he examined the intestinal villi three hours after- 

 wards; when the chyliferous vessels were turgid with chyle, and the 

 intestine was full of milky chyme mingled with a bilious-looking fluid. 

 In the white portion of the fluid, which was situate principally towards 

 the mucous membrane, numerous epithelium cells were found ; some 

 of which had evidently from their form been detached from the 

 surface of the villi ; whilst others have been thrown off from the inte- 

 rior of the follicles of Lieberkuhn. The villi were turgid, and destitute 

 of epithelium except at their bases. Each villus was covered by a 

 very fine, smooth membrane, continuous with what Mr. Bowman terms 

 the "basement membrane" of the mucous surface, which is reflected 

 into the follicles. The villi were semitransparent except at their free 

 or bulbous extremities, where they were white and nearly opaque. 

 The summit of each villus was crowded beneath the enveloping mem- 

 brane with a number of perfectly spherical vesicles, varying in size 

 from j^o <5 tn to 2^0 o tn f an i nc ^ > tn ^ matter in the interior of which 

 had an opalescent milky appearance. At the part where the vesicles 

 approached the granular texture of the substance of the villus, minute 

 granular or oily particles were situate in great numbers. The trunks 

 of two lacteals could be easily traced up the centre of each villus; and 

 as they approached the vesicular mass, they subdivided and looped; 

 but in no instance could they be seen to communicate directly with 

 any of the vesicles. These vesicles, in Mr. Goodsir's opinion, can 

 scarcely be considered in any other light than cells, whose lives have 

 but a very brief duration, which select from, and appropriate the ma- 

 terials in contact with the surface of the villi into their own substance, 

 and then liberate them, by solution or disruption of the cell-wall, in a 

 situation where they can be absorbed by the lacteals. When the in- 

 testine contains no more chyme, the developement of new vesicles 



1 Precis, &c., ii. 179. 



2 Edinb. New Philosophical Journal, July, 1842; and Anatomical and Pathological Ob- 

 servations, p. 4, Edinb., 1845. 



