266 HISTOLOGY OF THE MORBID PROCESSES. 



It must be borne in mind that changes which are morbid in a 

 given part of the body may be included in perfectly normal proc- 

 esses carried on in other parts, and are, therefore, not beyond the 

 pale of possible normal cellular activity. In fact, most of the 

 morbid processes observed find parallels in the physiological activ- 

 ities of some portion of the body. 



In bone, for example, it is a pathological condition when the 

 intercellular substance fails to be impregnated with earthly salts ; 

 but if such salts are deposited in the somewhat similar fibrous inter- 

 cellular substance of the closely related tissue forming a ligament, 

 the process is then morbid. The two tissues are closely related in 

 structure and are built up by cells having a common, not very remote, 

 ancestry : yet the uses the cells made of the materials brought to 

 them are, to us, very different, and, as yet, inexplicable. 



Nor do we know much concerning the way in which, or the 

 extent to which, normal conditions must be modified in order to 

 occasion visible morbid changes in the tissues. We do know that 

 apparently very slight alterations in those conditions may cause pro- 

 found tissue-changes, as is exemplified in the cachexia following 

 extirpation of the thyroid gland (see p. 183). The amount of 

 thyroid secretion allotted to individual cells of the body must be 

 almost infinitesimal, but its importance is strikingly demonstrated 

 when the cells are deprived of that supply. 



In this case we have at least an inkling of how slight an abnormal 

 condition may suffice to work profound alterations in the cellular 

 economy. When, therefore, we meet with evidences of a marked 

 disturbance of the processes within the cells of a tissue, or of their 

 formative activities, we need feel no surprise if an explanation of 

 the causes underlying those morbid manifestations is incomplete 

 or even entirely wanting. 



1. Albuminoid and Fatty Degenerations. These two forms of 

 degeneration are frequently associated with each other, and have so 

 much in common that they may well be considered together. They 

 both affect the cells of the parenchymatous organs, such as the 

 kidney, liver, and other secreting glands, the heart and other 

 muscles. 



Albuminoid, or " parenchymatous," degeneration results in a 

 swelling of the cells, with an increased granulation of their cytoplasm. 

 The granules are rendered invisible when acted upon by weak acids 

 or alkalies, and are considered to be of albuminoid nature. They 



