PRINCIPLES OF VETERINARY SURGERY 25 



and the tendinous tissue becomes completely regenerated. 

 The sheath usually remains slightly adherent at the point of 

 section. 



ELASTIC FIBRES.— The formation of elastic tissue is 

 a slow process. In wounds of the skin, the regeneration of 

 elastic elements does not begin for four or five weeks. The)^ 

 are always formed from the old elastic fibres which begin 

 sending out little delicate twigs from their sides, not from 

 their ends. These gradually grow toward one another and 

 finally unite to form an interlacing network of small elastic 

 fibrils. It sometimes takes years before they are of normal 

 size. The fact that elastic tissue is so slow in healing has a 

 marked influence in the repair of some abscesses. In poll- 

 evil, the ligamentum nuchae takes so long to granulate that 

 often the abscess is slow to heal ; a necrosis of the surround- 

 ing tissues and a purulent inflammation of the bursa may 

 bafifle the best treatment. 



FAT. — Formative tissue, fibrous connective tissue or 

 medullary tissue of bone may give origin to fat cells. The 

 nucleated protoplasmic remains of former fat cells divide 

 and multiply into large, round, mono- or multi-nuclear cells 

 — the fibro-blasts. These develop within the membrane sur- 

 rounding the original fat-cells (Diirck) and there manufac- 

 ture the globules of fat. 



The mature connective tissues possess different degrees 

 of regenerative power. It is most marked in ordinary fibrous 

 connective tissue, in periosteum and in the medullary tissue 

 of bone; whereas cartilage and bone substance proper pos- 

 sess but little ability to form new tissue. If they, are re- 

 paired, it is by proliferation of the cells of the periosteum or 

 of fibrous connective-tissue; otherwise the defects are filled 

 in with scar tissue. The connective tissues are able to change 

 from the one to the other by a change of the intercellular 

 substance only. This is called metaplasia. Cartilage may 



