142 CAPILLARY SYSTEMS. 



absorbents. The capillary systems are intermediate be- 

 tween the arteries and veins. Nutritive matter for all the 

 organs is by them separated from the blood. 



Q. How are the general capillaries divided? 



#. There are those which carry red blood ; those which 

 convey white fluids; and those giving passage to both red 

 and white fluids. 



Q. In what systems do the capillaries with red blood 

 predominate? 



*#. In the muscular tissue, in the spleen, in portions of 

 the mucous system, as the pituitary membrane. 



Q. In what systems do the blood and other fluids also 

 circulate?. 



e#. In the capillary systems of the osseous, serous, 

 some of the fibrous, the dermoid, and glandular tissues, 

 besides others. 



Q. How is this mixed circulation proved? 



/#. By the comparison of a piece of healthy serous 

 membrane in health and the same in a state of inflamma- 

 tion: by injecting the capillary system of the serous mem- 

 branes it exhibits a net-work of vessels not apparent in a 

 natural state: the appearance of the inflamed conjunctiva 

 is a remarkable illustration of the question proposed. The 

 proportions of the red and white capillaries vary in dif- 

 ferent textures; there are fewer red capillaries in the se- 

 rous tissues, while in the dermoid and mucous tissues they 

 preponderate greatly. 



Q. What hypothesis has Bichat connected with this ? 



. That there may be a set of empty vessels, which in 

 a natural state do not convey blood, but which are pre- 

 pared to receive it in cases of emergency. 



Q. What organs have white capillaries exclusively? 



