MUCOUS SYSTEM. 253 



mu co-purulent 5 in haemorrhage; in thickening of the mu- 

 cous membranes. They terminate rarely in gangrene. 

 This does take place in angina. 



Q. There is one remarkable termination omitted. 



/?. It is the formation of membranes as in croup and 

 in the intestines. 



Q. Is the morbid mucus alike in all the membranes ? 



t/2. It is not; it varies in them very much ; and even in 

 the same membrane at different periods the mucus is of 

 different colour and nature, becoming pus. 



Q. When mucous membranes are, from any unnatural 

 cause, disused, what takes place? 



/#. They contract and close. 



Q. What is the nature of the membrane lining fistulse? 



i/?. It is mucous. 



Q. On what do the morbid growths and enlargements 

 on the mucous membranes depend? 



t/?. On morbid action and development of the mucous 

 capillaries, from long-continued irritation and chronic in- 

 flammation. 



Q. What are the causes of mucous haemorrhage? 



t#. They are from exhalation and disorganization, not 

 from rupture. 



Q. Whence may exhalation of blood in mucous mem- 

 branes arise? 



#. From an exaltation or diminution of the vital forces 

 of the membranes. Hence the active and passive haemor- 

 rhages. 



Q. What is the pathology of aphthae? 



. They are either little tubercles ulcerated, or small 

 tumefied glands. 



