FATTY CHANGES IN THE HEART. 573 



ordinary circulation, and totally so to act with safety in cases 

 of severe exertion. 



When examining a heart thus affected, we may observe, 

 both on the surface beneath the lining and covering mem- 

 brane, and throughout the interior of the substance of the 

 walls, variously distributed pale or buff-coloured spots, also 

 that the entire substance feels softer than natural. 



Examined more minutely, we find that these paler patches 

 are the changed muscular fibres, in which the healthy trans- 

 verse markings and nuclei are absent, and that their place is 

 occupied by fat or oil globules, with some other amorphous 

 material. The muscular structure is found in a great measure 

 to have lost its tenacity ; it is more brittle, and seemingly less 

 capable of resisting any strain wliich may be put upon it. 



Any clinical phenomena which may attend either of these 

 conditions cannot be said to be diagnostic ; they may indicate 

 disturbance or textural alteration of the heart, but not such as 

 will lead us, apart from other information, to hazard with any 

 degree of safety an opinion as to the existence of such changes. 

 Both conditions, of fatty metamorphosis and fatty infiltration 

 of the heart's structure, may occur in the heart individually 

 and separately, or they may be associated with similar changes 

 and deposits in other organs and structures of the body. 



IV. KUPTUEE OF THE HeART. 



This lesion, although not what may be properly termed 

 chronic, seeing it is always of sudden development, is in many 

 instances but the natural result of some antecedent diseased 

 condition. In any instance, either apart from minute struc- 

 tural change, or as the result of certain degenerative processes, 

 it is a rare lesion. 



The immediate causes of cardiac rupture, from the records 

 of such cases as have been reported, and from my own ex- 

 perience, I am disposed to regard as over-exertion, and con- 

 cussion or shock ; these latter usually the result of a fall, or of 

 violence applied directly to the chest- walls. 



Mr. Percival, in his ' Hippopathology,' gives one instance of 

 rupture of the right auricle in a horse immediately succeeding 

 a hard-contested race. From my o-\vn experience I must cor- 

 roborate what Mr. Gamgee, in ' Domestic Animals in Health 



