CHANGES IN PANCREAS, PHOSPHORUS POISONING 243 



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The luitochondria in the normal pancreas of the white mouse 

 differ in no noteworthy })artieuhir from the mitochondria in the 

 pancreas of other animals, which, indeed, have been described 

 again and again (for reference see Bensley '11, p. 361). At- 

 tention, however, may be called to the fact that the mitochondria 

 are filamentous, that they occupy the basal zone of the cell and 

 that they possess bleb-like swellings all of which can easily be 

 distinguished in the living cells. This may be seen by reference 

 to figure 1. 



The first change resulting from a very mild degree of phos- 

 phorus poisoning consists of the loss of the swellings on the 

 mitochondrial f laments (fig. 2). At the same time the mito- 

 chondria become shorter and thicker. Some of them appear 

 spherical, others ovoid. These altered mitochondria can be 

 clearly distinguished from the zymogen granules by their stain- 

 ing reactions. The zymogen granules stain a purple or an olive 

 brown color depending upon the degree of differentiation, and 

 the mitochondria bright crimson with the fuchsin methyl green 

 stain. This alteration in the mitochondria precedes any notice- 

 able change in the other cell constituents. The nucleus still 

 stands out sharply, the nuclear membrane being quite distinct, 

 the cytoplasm stains a homogeneous bright green color, and 

 the zymogen granules occupy the distal zone of the cell. 



The second stage of the process is represented in figure 3. 

 It can readily be seen that the mitochondria exhibit a remarkable 

 tendency to clump together like agglutinating bacilli. The 

 clumps occur most frequently in the basal portions of the cells. 

 They are of variable size. Some of them are composed of only 

 three or four mitochondria. In others, however, it is possible 

 to count eighty or even more individual granules. The clumps 

 vary in consistency, some of them being loose and others quite 

 compact. The mitochondria are more closely crowded in the 

 center. But even here the individual granules may be dis- 

 tinguished from one another by the reflection from their curved 

 surfaces. The peripheral part of such a clump contains mito- 

 chondria less densely packed together. Strands, three or four 



