GENERAL DISEASES. 341 



of the heart, as well as on the externa:! part of that viscus, 

 was an irregular rent two inches long. It crossed the valve 

 of the heart, which was very thin in this place. The size of 

 the heart was very small, considering the height and bulk of 

 the dog. The walls of the ventricles, and particularly of the 

 left ventricle, were very thick. The cavity of the left ven- 

 tricle was very small ; there was evidently a concentric hyper- 

 trophy of these ventricles ; the valve of the heart was of 

 great size. 



" The immediate cause of the rupture of the valve of the 

 heart had evidently been an increase of circulation, brought 

 on by an increase of exercise ; but the remote cause con- 

 sisted in the remarkable thinness of the valve of the heart. 



"This case is remarkable in more than one respect: first, 



because instances of rupture of the valve of the heart are 



very rare ; and secondly, because this rupture had its seat in 



the left valve of the heart, while usually, in both the human 



being and the quadruped, it takes place in the right, and this 



without doubt because the walls and the valves of the right 



side are thinner."* 



•Youatton "The Dog." 



