426 Veterinary Medicine. 



secure its aeration. Sometimes this fails to be effected, and ven- 

 ous blood from the right side of the heart continues to mix with 

 arterial in the left, deteriorating it in quality and unfitting it for 

 nutrition, secretion, calorification and other essential processes. 

 The semi-venous blood circulating in the arteries gives a bluish 

 hue to the visible mucous membrane, hence the name of the blue 

 disease. This blood is unfit for sustaining the vital changes 

 essential to the production of animal heat, so that the animal 

 suffers from coldness of the surface and extremities, staring coat 

 and general unthrifty appearance. Such subjects grow badly, 

 and refuse to lay on flesh, but are said to arrive at maturity in 

 some instances and to have their imperfection recognized only 

 because of the short breathing and irregular heart's action when 

 subjected to exertion. A heart murmur preceding the first 

 sound of health is usually present, as in anaemia. 



Drs. Abernethy and Wardrop draw attention to the frequency 

 of pervious foramen ovale in the human subject in connection 

 with pulmonary consumption, and opine that it is reopened as a 

 consequence of this disease. The coincidence has not been ob- 

 served in the lower aninals, though, if it were found to exist, the 

 question would arise whether the deterioration of the blood and 

 general health in o^ext. foramen ovate did not also favor the de- 

 posit of tubercle in the lungs. When from deficient ventilation 

 the atmosphere and blood become impregnated with carbonic 

 dioxide, the production of tubercle in man or in animals is corre- 

 spondingly frequent. 



The subjects of pervious foramen ovale die young or prove 

 worthless when they arrive at maturity. Nothing can be done 

 to ameliorate the condition. 



