30 MANUAL OF EQUINE MEDICINE. 



THE METAMORPHOSES.— There are three varieties; 

 viz., fatty, mucoid, and colloid degeneration. 



Eatty Degeneration. — This variety of degeneration is 

 characterized by the direct conversion of the albuminoid 

 substance, of cells or fibres, into fat. The cells or fibres 

 enlarge at first and then break up, and the fat is thus dis- 

 tributed in the tissues. Caseation is a modified form of 

 fatty degeneration. 



The common causes of fatty degeneration are senile 

 decay, deficient blood-supply, diminished vitality, congestion 

 and inflammation. 



Mucoid Degeneration. — In this form the albuminous 

 intercellular substance, and far more rarely the cells, 

 become liquefied and converted into a substance called 

 mucin. Mucin is precipitated by acetic acid, and contains 

 no sulphur, thus differing from albumen. 



Colloid Degeneration. — In this form the albuminous con- 

 tents of the cells (and not the intercellular matter) are con- 

 verted into a jelly-like material called colloid, which differs 

 from mucin in containing sulphur, and in not being precipi- 

 tated by acetic acid. 



THE INFILTRATIONS.— There are four varieties of 

 infiltration; viz., fatty, lardaceous, calcareous, and pig- 

 mentary infiltration. 



Fatty Infiltration. — In this form fat is deposited within 

 the cells as distinct globules, which increase in size and tend 

 to coalesce. 



The protoplasmic cell contents are at first merely pushed 

 aside, but they subsequently atrophy. As an example of 

 fatty infiltration may be mentioned the conversion of 

 connective into adipose tissue. It is due to the presence of 

 fat in blood, in greater quantity than can be consumed by 

 the economy. 



This in turn may be due on the one hand to excess of 



