572 CHRONIC DISEASES OF THE HEART. 



elements of the tissue. Although not recognised as of so 

 much importance because occurring less often in our patients 

 than in the human subject, these conditions are still, with many 

 animals which come under our notice, a very serious matter, 

 and of more frequency than is believed. When occurring, they 

 are often associated with other unnatural states, specially with 

 dilatation, partial or general, of the cardiac cavities ; and with 

 this operate prejudicially by largely impahing function, and 

 offering facilities for other lesions Avhich may prove rapidly 

 fatal. 



a. Fatty Infiltration. — In many of our patients, where their 

 treatment has for some time been highly artificial, where, in 

 particular, from a want of exercise sufficient to maintain the 

 system in a healthy and vigorous state, there is a disposition 

 for the excess of nutriment to be stored throughout the 

 different structures of the body in the form of fat, we find 

 that the heart, in connection with many other organs, partici- 

 pates in this accumulation of adipose structure. In these 

 cases, in addition to the ordinary situation of fatty tissue 

 around its base and at the origin of the great vessels, it is 

 found that this tissue insinuates itself amongst and between 

 the muscular fasciculi and ultimate fibres. Although this con- 

 dition is not what is meant when we speak of fatty degenera- 

 tion proper, it is yet highly probable that by this intermingling 

 of fat with the muscular fibres these may be impoverished, 

 injured, or paralyzed, or it may even be the active means in 

 the production of that more serious state — 



h. Fatty Metamorphosis, or Degeneration. — Here, in addi- 

 tion to simple atrophy of the fibres and loss of their func- 

 tional power in consequence of the atrophy, we have a re- 

 moval of the sarcous elements, and their replacement with 

 fat granules or globules and other amorphous material, the 

 result of the disintegration of the intimate muscular elements. 



By this degenerative change the integrity and action of 

 these are ultimately destroyed, nor can they be again restored. 



The great majority of cases where this true fatty degenera- 

 tive change — not the mere infiltration of the substance of the 

 organ with fat — occurs, are those also where thinning of the 

 walls with enlargement of the cavities exists, resulting in the 

 condition of a truly weak heart, very unfit even to carry on 



