1894.] 



MICROSCOPICAL JOURNAL. 



151 



Pancreas, four hours 

 after eat i ng . Cal*. 



%^^ 



i^% 



the same closed alveoli. The alveoli of the organ, how- 

 ever, are not so often circular in cross-section but are 

 more elongate, so that the organ is less strictly a race- 

 mose gland than is the parotid. 

 The section illustrated is drawn 

 to show the different appearance 

 ^0 of the gland alveoli at different 

 hours of the day, for in the pan- 

 creas there is a marked difference 

 in the shapes of the cells, this de- 

 pending on the time after the an- 

 imal partook of its last meal, when 

 it was killed. In the case of the 

 active organ during the period of 

 digestion, while being compelled 

 through the nerves to furnish its 

 product to the intestine, the cells 

 are shrunken so that the central 

 lumen is clearly visible and the 

 cell-walls themselves are also evi- 

 dent. 



A few hours after the act of digestion while the organ is 

 having a chance to partake, like the cells of the body at 

 large, of the results of digestive work, the cells of the or- 

 gan fill themselves with their peculiar material, out of 

 which they can construct trypsin, their specific secretion, 

 this they do in preparation for the next meal. The cells 

 in an organ of an animal killed at such a time are 

 so far swollen by the accumulation of this material that 

 the cell boundaries are wholly or nearly obliterated 

 while the lumen is also seen with difliculty if at all. It 

 is because the animals are so likely to be killed in this 

 condition that as a rule sections of the pancreas exhibit 

 cells so indistinctly. Figure 1 of the cut was drawn 

 from nature, from a pancreas of cat four hours after a 

 full meal. Figure 2 is from a " resting pancreas" and 



