THE GENERAL CONDITIONS OF LIFE 323 



The whole difference lies in the fact, as has been set forth by 

 Korotneff ('92), that where a very rapid disappearance of the 

 tissue is concerned, the leucocytes exercise greater activity and 

 begin their work earlier. Among the atrophies in normal life 

 belong, further, the phenomena of senile atrophy, which consists 

 in a very slow and constantly progressive degeneration of the 

 various tissues, and is never wanting in extreme old age. 



Next to the normal atrophies are the pathological ones, which 

 appear in the organism when diseases have created the proper 

 conditions for them. Thus, e.g., in human beings the muscles 

 of the leg atrophy when, as a result of disease, the knee-joint has 

 become ossified and immovable. Such atrophies, which occur as 

 a result of disuse of the organ, are termed, simply, atrophies from 

 disuse. In these pathological atrophies the processes are, in 



\ 

 ' , A 



FIG. 137. Degeneration of leucocytes in acute leukaemia. 7 and //, Normal leucocytes ; the 

 dark mass is the cell-nucleus, the clear border, the protoplasm. /// VII, Stages of the dis- 

 solution. (After Gumprecht.) 



general, the same as in normal ones; nevertheless, at times re- 

 markable phenomena appear. Thus, in muscles that have atro- 

 phied because of disease, a very great increase of nuclei is 

 frequently found, while Loosswas able to determine with certainty 

 that in the muscle-atrophy of the histolytic tail of the tadpole the 

 nuclei were neither increased nor diminished. Further, the 

 tissues atrophying because of disease are at first, as a rule, much 

 more solid and compact than those that undergo normal histolysis 

 a circumstance that is perhaps based upon the considerably longer 

 duration of the pathological atrophy, during which the dissolved 

 masses have more time to be discharged. But these are all 

 special, accessory factors. 



The degeneration of leucocytes has recently been followed in 

 detail especially by Gumprecht ('96) in acute leukaemia. It 

 is interesting, since the dissolution of the nucleus takes place in a 



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