PART II. 



HISTOLOGY OF THE MORBID 

 PROCESSES. 



CHAPTER XX. 

 DEGENERATIONS AND INFILTRATIONS. 



As the result of disturbances in the internal economy of the cell, 

 a variety of changes, called degenerations or infiltrations, are occa- 

 sioned, some of which are accompanied by visible alterations in the 

 structure of the cell or of the intercellular substances. We are so 

 ignorant of the exact nature of the normal processes carried on by 

 the cell that it is impossible for us to furnish an explanation of most 

 of these changes due to abnormal conditions. We can only describe 

 and group the results according to their apparent likenesses until 

 such time as an increased knowledge permits a more enlightened 

 conception of their significance. 



The degenerations are changes in which one of the results is the 

 conversion of a part of the normal structure into some other sub- 

 stance. They imply a loss on the part of the tissue-elements suffer- 

 ing the change. 



The infiltrations are departures from the normal in that material 

 from without is deposited either within or between the tissue-ele- 

 ments in an abnormal form or degree. They imply a gain of 

 material, but not necessarily an advantageous gain, on the part of 

 the tissues affected. 



Such general statements of an obscure subject must inevitably be 

 vague. They are largely based upon theoretical considerations, and 

 it becomes difficult in many cases to decide definitely whether a 

 given condition is due to degenerative changes or is the result of 

 infiltration, or whether both processes may not have contributed 

 toward producing the abnormal appearances which are observed. 



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