RF.TROi-.RKSSlVl-; TISSUE CHANGES. 



lU 



portion of the blood vessels of tissues affected with chronic in- 

 flammation and in the blood vessels of sarcomata. It has also 

 been (_ibscrved in \-(_duntary and heart ninscle in certain diseased 

 processes. 



Hyalin, an albuminous substance ^•ery similar to am\din, does 

 not respond to the iodine test, and is not acted upon b)- alcohol, 

 ether, chloroform, acids, ammonia, or water. .\cid stains, as 

 eosin ami acid fuchsin, have an affinitv for hyalin and stain it 

 quite intensel}'. 



Etiology. — The specific cause of hyaline formation is not 

 definitelv known. Certain predisposiniL^ factors, ho\ve\-er, are of 

 interest. Wells found that lactic acid injected into \-riluntary 

 muscle \\'as succeeded bv h}'aline formation, and it mav be as- 

 sumed that the cause of hyaline chan<;-es in \-olnnlar\- muscle is 

 excess of sarcolalic acid. Srmie diseased processes, as chronic 

 inflammation, tuberculosis, and sarcomatosis are accompanied 

 by conditions that favor h}-alme formation. 



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91. . 



Fig-. 115 — Hyaline ncneerratinn, \'.'ssels. 

 Hyaline amund arteries in maxilla of colt. 



Appearance. — Macroscopic. — Rarely does this condition Ijc- 

 come sufficientlv marked to be rectfgnized with the unaided 

 eye. The hyaline substance appears as a translucent, homogen- 

 eous, firm mass, intermingled with the normal tissue. 



Microscopic. — The hyaline substance appears as glas.?y areas, 

 and the adjacent tissue frequently becomes less distinct. Except 

 for the affinity of hyaline substances for acid stains and its fail- 



