MUSCULAK FIBEE-CELLS DEVELOPMENT. 391 



The smooth muscular fibre manifests the rigor mortis, like the 

 striated (p. 405). 



Development of Muscular Fibre- Cells. 



There is nothing peculiar in the development of muscular fibre- 

 cells. They are formed merely by the elongation of cells originally 

 rounded; the cell- wall disappearing (in most cases, at least) after 

 forming the homogeneous soft substance already described the 

 musculine. 



The nutrition of smooth muscle is probably very active, though 

 less so than that of striated muscular fibre. Lehmann's investi- 

 gations in regard to the fluid which bathes the fibres show that it 

 has an acid reaction, and contains creatine and inosite, besides lactic, 

 acetic, and butyric acid. 



Regeneration of Smooth Muscular Fibre. 



It is not certainly known whether this kind of muscular fibre is 

 reproduced in cases of loss of substance. It is, however, probably 

 not reproduced, but is replaced by areolar tissue. 



Pathological Conditions and New Formations of Muscular Fibre-Cells. 



Smooth muscular fibre is liable to hypertrophy and to atrophy, 

 like the striated form. It also becomes paralyzed like the latter, 

 and is very liable to fatty de- 

 generation. "* m 



Pathological new formations of 

 this tissue occur in some cases of 

 uterine tumors. 



1. Hypertrophy of the smooth 

 muscular fibre is usually of limit- 

 ed extent, and recognizable even 

 by the naked eye, by the pale-red 

 fibrillation. Occurring in the py- 

 loric portion of the stomach, this 

 part sometimes becomes an inch 

 or more thick, the circular fibres 

 being mainly increased. An are- ; ransverse section " ot the hypertrophied mu8 . 



Olated appearance IS produced in cular layer of the stomach, boiled in acetic acid, 

 the hypertrophied maSS by the and dried, a, a. Smooth muscular fibres, divided 



development at the same time of tran8 sel y- . * ^woiar tissue bundles, 

 the areolar tissue surrounding 



the fasciculi, and which increases in thickness towards the submu- 

 cous tissue. In certain layers of the muscular coat, flattened cells 

 are met with, resembling epithelial cells, but having an oblong nu- 



