INTEENAL EESTITUT1VE SECEETIONS 



281 



by the anabolic action of the granules ; the black spherules of 

 increasing size observed later on would have nuclei composed of 

 the elementary granules, which are invisible because they are 

 surrounded by a more or less extensive layer of newly formed fat. 

 The credibility of this hypothesis is proved by the observations of 

 Altmann and Krehl on fat absorption in the mammalian intestine. 

 The epithelial cells, in the early stages of absorption, exhibited 

 not grey or black granules, but blackish rings with clear centres 

 (Fig. 93). This appearance can only be interpreted by assuming 

 that the clear centres consist of unstained elementary granules 

 with a layer of fat at their outermost zone, which fat reached the 

 cells in the form of solution, and was regenerated by the anabolic 

 activity of the granules. These important cytological observations 



B 



.V : *> ' "' ?*' 



t-.- 







& 



' 







PIG. 03. Fragments of epithelium from mammalian intestine during fat absorption. (Krehl.) 

 About 700 diameters. A, suckling kitten, 3 hours after artificial feeding with cream ; 

 B, white rat, 3 hours after feeding with cream. 



seem to us to afford direct evidence for the modern theory of the 

 absorption of fats in the form of solutions. 



Other physiological arguments in favour of this theory may be 

 deduced from the great importance of the pancreatic juice and the 

 bile in the absorption and utilisation of alimentary fat. We saw 

 in the last chapter that the lipolytic action is due to the pancreatic 

 juice and that the bile has a marked coadjuvant action upon it, as 

 is confirmed by the effects of intestinal acholia (see p. 220 et seq.). 

 It is therefore important to consider the effects of extirpation of 

 the pancreas and deviation of the bile from, the intestine more 

 closely in regard to fat absorption. 



Minkowski's pupil Abelmann (1890) made a great number of 

 experiments on fat digestion and absorption in the animals from 

 which Minkowski had removed the pancreas. He found that after 

 complete extirpation of the pancreas in dogs, the whole of the 

 alimentary fats (butter, lard, olive oil) reappeared in the faeces so 

 that no absorption had taken place. The sole exception was the 



