FLUID OF SEROUS MEMBRANES. 



193 



possess, as do the stomata of the surface, both true and false, consider- 

 able importance in a pathological point of view, for it is in connection 



Fig, 133. 



Fiff. 133. — Portion of Serous Membrane of Diaphraom ^Pleural) from the 

 Rabbit, treated with Nitrate op Silver after Removal of Superficial Epi- 

 thelioid Later. (Recklinghausen.) 



c, c, ceU-spaces of tissue ; d, d, commencing lymphatic vessels connected at h, h, with 

 the cell-spaces. 



with them that proliferation is apt to occur in chronic inflammation of 

 the serous membranes. 



The nerves of the serous membranes are destined chiefly for the 

 blood-vessels, and for the most part accompany these in their course. 

 A few pale_ fibres, however, arc distributed to the substance of the 

 membrane, in which they form a plexus with large meshes ; from the 

 branches of this, fibrils may be traced which unite into a somewhat 

 finer plexus near the surface. 



Fluid. — The internal surface of serous cavities is moistened and lubricated -with 

 a transparent and nearly colourless fluid, which in health exists only in a veiy 

 small quantity. This fluid, Avhich is doubtless derived from the blood-vessels of 

 the membrane, has been commonly represented as similar in constitution to the 

 serum of the blood. But it was long since remarked by Hew son (and a similar 

 opinion seems to have been held by Haller and Monro), that the fluid obtained 



