NECROSIS AND DEATH. 261 



around the necrotic area of a filirous or osseous capsule, or even 

 cause a fibrous formation throughout the entire necrotic mass. 

 From the foregoing it is apparent that necrotic tissue may be 

 disposed of as follows: 1. Abscrptiun. 2. Exfoliation. 3. En- 

 capsulation. 4. Sequestration. 



Absorption. — The necrotic mass is more readily absorbed 

 when it is in a liquid state (colliquation) , although leucocytes, 

 and various other cells may produce enzynis that are capable of 

 dissolving coagulated necrotic tissue. Absorption of lluid ne- 

 crotic tissue is in part accomplished bv means of the h niphatic 

 tissues, and in part by means of leucocytes that incorporate and 

 convey fragments of necrotic cells to the variijus organs that 

 dispose of waste materials. Necrotic infarcts are occasionally 

 entirelv absorbed. 



E.r] oliatioii. — Necrotic surface tissue is frcquentlv disposed 

 of by separation of the dead frnni the living tissue as a result oi 

 inflammation or contraction of the necrotic mass. The separated 

 necrotic mass is the sphacelus. The process of separation and 

 sloughing is exfoliation. ILxfoliation is the usual disposition of 

 necrotic extremities induced by freezing and bv ergot poisoning. 



Eiicapsulatioji. — The irritation (iroduced by su))surface ne- 

 crotic tissue may be insufficient to cause an acute inflammation, 

 but it may stimulate til>rous hyperplasia. Thus a fil)rous capsule 

 or wall is built around the necrotic mass, i. e., it becomes encap- 

 sulated. In some instances the encapsulated necrotic tissue later 

 becomes calcified, or it may become liquefied, the capsule retain- 

 ing the liquid, thus a cyst is formed. 



Fibroblasts mav extend into the necrotic area and form 

 fibrous tissue throughout the entire mass, thus there would be 

 a mass of cicatrizing fibrous tissue i)ermeating the necrotic 

 mass. 



Sequestration. — This is a term applied to the separation of 

 subsurface necrotic tissue, more especially necrotic bone, from 

 the surrounding healthy tissue. The separate necrotic portion 

 is termed the sequestrum, and the process of its separation 

 sequestration. Art osseous secpiestrum may be encapsulated, the 

 capsule later becoming osseous, thus forming an involucre. 



Effects. Necrosis is the condition resulting from tissue des- 

 truction. The effects of tissue destruction depend upon the 

 variety of tissue, the exient and location of the condition, and 

 the age and condition of the animal in which it occurs. If the 

 tissue destroved is capable of regeneration, or if it is limited in 

 extent, and the animal is otherwise in good '-ondition, the effects 

 will be insignificant. If the tissue destroved cannot i.e regener- 



