418 ABSORPTION OF FAT. [BOOK n. 



Within the columnar cell the fat may be seen, both in fresh 

 living cells, and in osmic acid preparations, to be disposed in 

 globules of various sizes, some large and some small, each 

 globule placed in a space of the protoplasmic cell substance. It 

 does not follow that the fat actually entered the cell exactly in 

 the form of these globules; it may be that the fat passes the 

 striated border in very minute spherules which, reaching the 

 body of the cell, run together into larger globules ; but whether 

 this is so or not we do not know. 



From the columnar cell the fat passes into the spaces of the 

 reticular tissue of the villus. It has, it is true, been contended 

 that it passes along the substance of the bars of the reticulum ; 

 but in carefully prepared osmic acid specimens of a villus in 

 active digestion of fatty food, the fat may be distinctly recog- 

 nized as largely filling up, still in the form of globules of vari- 

 ous sizes, the spaces in the meshes of the reticulum which are 

 not occupied by the leucocytes or allied wandering cells. The 

 bases of the columnar cells, through the gaps in the basement 

 membrane, directly abut upon the labyrinth of spaces ; and the 

 fat once out of the base of the cell is free in the spaces of this 

 labyrinth. How it issues from the cell we do not exactly know: 

 possibly by a process analogous to the excretion of solid matters 

 by an amoeba. 



From the labyrinth of spaces of the reticulum of the villus 

 the fat passes into the cavity of the lacteal radicle ; and it is 

 worthy of note that in the passage it undergoes a change. In 

 the interior of the intestine, in the substance of the columnar 

 cell, and apparently in the labyrinth of the reticulum it is 

 simply emulsified fat consisting of globules small and large; 

 within the lacteal radicle it consists partly of the same easily 

 recognized globules but partly of the extremely divided 4 molec- 

 ular basis ' ( 241) ; it is now no longer emulsified fat but 

 chyle. How and by what means this extremely minute division 

 of the globular fat into the 4 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. 



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 sub- 

 stance of the villus past the capillaries, though not proved, must 

 still be considered as possible. 



