Structure of Smooth Muscle. 49 Y 



Van Geliucliten, 188U, dcscrihcd nuclei in ihe smooth muscle of the 

 frog, which show a distinct spiral form. Kegarding their significance 

 ho says nothing. 



Ranvier, 1889, by injecting lemon juice into the gall-bladder of 

 the guinea-pig and afterwards fixing in osmic acid obtained distinct 

 cross-striations in the smooth muscle fibers which he interpreted as 

 contraction phenomena. 



Apathy, 1890, in support of Englemann's inotagmen theory for the 

 contraction of striated muscle, proposed a similar theory for smooth 

 muscle. According to his theory during contraction the chemical 

 composition of the sarcoplasm immediately surrounding the nucleus 

 is so altered that the interfibrillar sarcoplasm draws water from it. 

 In consequence the myotibrilhe embedded in this sarcoplasm swell, 

 becoming at the same time shorter. This in turn causes the shorten- 

 ing and thickening of the entire fiber. Relaxation is the reverse 

 phenomenon. 



Klecki, 1891, found that the intercellular bridges are more numer- 

 ous and longer in contracted than in uncontracted muscle. At times 

 in uncontracted muscle they are entirely absent. He gives no further 

 description of contraction. However, in his figures he shows some 

 fibers staining lightly, others darkly, in cross section. The dark 

 fibers are the smaller. Which be considers the contracted fibers he 

 does not state. 



Roule, 1890-1891, studying contraction in smooth muscle, came to 

 the conclusion that it is brought about by the myofibrillse, which 

 decrease in length and increase in thickness. 



In his article on intercellular bridges in smooth muscle, Barfurth, 

 1891, did not discuss contractility. However, his figures taken from 

 cross-sections of the fibers show dark and light fibers, both of equal 

 thickness. 



Werner, 1894, found that smooth muscle fibers, left some time in a 

 warm oven, show distinct cross-striations and strongly wrinkled con- 

 tour. 



Drasch, 1895, in the smooth muscle of the poison-glands of Sal- 

 amander maculosa, in contracted fibers, described cross-striations. 

 He thought they were due to a wrinkling of a membrana propria and 



