138 VASCULAR SYSTEM. 



fl. But one kind of blood enters, and less of that; an 

 interruption to all communication between the general 

 and abdominal black blood system takes place, and a 

 diminished size of the liver. 



Q. At what period of life is the circulation in the ab- 

 dominal system of black blood most active? 



<fl. From the thirtieth to the fortieth year; and it is at 

 that period that diseases of the abdominal system ap- 

 pear. 



Q. What are these diseases? 



*ft. Haemorrhoidal affections, and melancholia. 



Q. Do you ever see ossification in this system? 



rf. Never. 



PATHOLOGY OF THE VASCULAR SYSTEM WITH BLACK 

 BLOOD. 



Q. What are the diseases of the veins ? 



*#. They are few, and imperfectly understood. There 

 is inflammation or phlebitis; dilatation; contraction; and 

 concretions in the veins. 



Q. Name a remarkable pathological contrast in the state 

 of the arteries and veins in fever. 



Ji. While the arteries are in tumultuous action, the 

 veins are quiet as in health. 



Q. What are the causes of inflammation of the veins? 



*#. The cause is sometimes unknown; usually it arises 

 either from wounds of the veins, or from ligatures, as in 

 varicose veins after an operation, or from inflammation of 

 surrounding tissues, or from a varicose state. 



