518 ABSORPTION OF FAT. [BOOK n. 



extremely minute division of the globular fat into the ' molecular 

 basis' takes place we do not know; nor do we know the exact 

 manner in which the fat passes from the spaces of the reticulum 

 into the interior of the radicle. If the sheet of sinuous epithelioid 

 plates which forms the sole wall of the chamber is discontinuous, 

 presenting here and there gaps between the plates, the passage 

 presents no difficulty in itself, but does raise the difficulty why 

 there is so great a difference between the chyle inside the chamber 

 and the fat outside. On the other hand, if as observations seem to 

 shew the lining in question is actually continuous, the fat must pass 

 into the lacteal radicle either through the substance of the plates 

 or through the junction lines of cement. Such a passage presents 

 difficulties; but at the same time we can conceive that in the 

 struggles of such a passage some of the fat might be converted 

 into the molecular basis. 



We may here perhaps remark that the contents of the lacteal 

 radicle consist not exclusively of fat, but of fat accompanied by 

 the proteid and other substances which go to make up the chyle. 

 Proteid and other substances besides fat are also present in the 

 lymph which occupies in part the labyrinth of the body of the 

 villus, and are derived, like the lymph elsewhere, from the blood 

 of adjacent capillaries; at least, they are in part so derived, 

 though it may be not wholly, for as we have just seen the passage 

 of proteid material from the intestine into the substance of the 

 villus past the capillaries though not proved, must still be con- 

 sidered as possible. 



We have seen ( 262) that the spaces of the reticulum of the 

 villus are more or less occupied by wandering cells of which we 

 spoke under the general term of leucocytes. These do not all 

 present the same appearances and most probably are not all of the 

 same kind. A number of them may be distinguished by the fact 

 that the cell body is loaded with discrete granules which stain 

 readily and deeply with certain anilin dyes, and which though not 

 of a fatty nature turn black with osmic acid. 



Some of these leucocytes wander not only through the labyrinth 

 of the reticulum but pass into the epithelium between the cells, 

 and may project processes into, or even make their way eventually 

 into the interior of the intestine ; or following the reverse course 

 may wander from between the epithelium cells into the body of 

 the villus; some of them moreover undoubtedly contain fat. 

 Hence the view has been suggested that these leucocytes are 

 important agents, indeed the chief agents in the absorption of fat. 

 It has been supposed that they, receiving the globules of fat into 

 their cell substance, in fact eating the fat exactly after the manner 

 of an amosba, either while projecting between the columnar cells, 

 in which case they carry their burden of fat through the epithelium 

 into the villus, or while wandering in the labyrinth of the villus, 

 bear it away bodily into the lymphatic system. But the number of 



