ETIOLOGY OF BERIBERI. 383 



lobules and sometimes in the central portions the capillaries are 

 widely distended with blood and the arrangement of the 

 cells is distorted. The individual cells show various grades of 

 changes. In some the protoplasm is the seat of small vacuoles 

 while in others the protoplasm has entirely disappeared, leaving 

 a more or less intact nucleus enclosed by the cell membrane — all 

 grades of this change from slight vacuolation up to complete 

 disappearance of the protoplasm may be traced. The nucleus 

 sometimes remains intact, while in others can be seen various 

 stages of disappearance of the chromatin, until simply the 

 shadows of some cells are left. In other areas another type of 

 cell change takes place in which the cell outline is clear but dis- 

 torted and the cell protoplasm is much more opaque, more homo- 

 geneous, and more highly acidophilic than normal. Some of this 

 latter type of cell contain apparently intact nuclei and some even 

 double nuclei, while in others various grades of disappearance 

 of the chromatin are seen down to those in which the nucleus 

 is no longer visible. 



While the congestion in these areas is intense, in no place 

 has actual haemorrhage taken place. No marked bile stiasis is 

 recognizable; sections stained with Sudan III show only a very 

 small amount of fatty degeneration. 



A few leucocytes surround some of the central veins, and, 

 if regeneration be present, it is certainly not a prominent feature. 



Spleen. — The spleen shows some congestion and a rather loose 

 arrangement of the reticulum of the pulp. The congestion is 

 especially marked in the region of the lymphoid follicles- The 

 follicles are relatively small. No other notable changes are seen. 



Pancreas. — The pancreas is well formed and shows no changes 

 outside of the islands of Langerhans. Here the cells are very 

 pale and very poorly differentiated from one another, while the 

 nuclei are relatively prominent. Occasionally double nuclei are 

 seen. No changes are seen in the periacinar tissue. The aver- 

 age size of the islands is large, but not larger than within 

 normal limits. 



Kidneys. — These show a very severe acute parenchymatous 

 degeneration and some congestion. Little, if any, exudation of 

 cells has taken place. Dilated veins are seen on the surface and 

 a few very small areas of superficial fibrosis. 



The convoluted tubules show a marked degeneration of the 

 epithelial cells, and practically all are filled up with a substance 

 which is acidophilic and arranged in the form of a granular 

 reticulum — this is evidently a coagulated, albuminous fluid. The 



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