FATTY DEGENERATION. 233 



the bioplasm, which depend upon an irregularity in 

 the order of occurrence of the developmental phe- 

 nomena. 



In some pathological alterations an adventitious 

 texture is formed outside a vessel by the multiplica- 

 tion of the masses of bioplasm of the tissue itself, as 

 well as of the corpuscles resulting from the growth 

 and detachment of buds or offsets from the white 

 blood-corpuscles which have passed through the capil- 

 lary walls with serous fluid (exudation). Collections 

 of bioplasm are thus formed which give rise to altera- 

 tions in the neighbouring tissue. An elastic trans- 

 parent tissue, such as that of the fibrous coat of an 

 artery, would lose its elasticity, and, in consequence, 

 become friable and rotten. Gradually the bioplasm 

 itself undergoes change, and at last dies. Fatty 

 matter, cholesterin, and earthy phosphates are among 

 the resulting products, and these remain outside or 

 amongst the tissue of the vessel, interfering with the 

 due performance of its function. 



Fatty degeneration takes place in muscles that 

 have remained for some time out of use, and in many 

 of the lower animals it may be induced simply by 

 keeping them in acid for some time. A beautiful 

 example is represented in PL VI, figs. 4, 5, p. 222. The 

 specimen of which this is a copy was taken from the 

 abdominal muscle of a little hyla, or green tree frog, 

 that had been kept many mouths in confinement. 

 Not an indication of contractile tissue remains. The 

 whole contents of the sarcolemma have disappeared, 

 and fat globules are seen to be substituted for them. 

 The capillary vessels were still pervious, and blood 

 was distributed to the muscle during life, fig. 5, PI. VI, 

 p. 222. It is clear, therefore, that the fatty change 

 is not due solely to insufiicient supply of nutrient 

 pabulum but depends upon other circumstances. 



