Structure of Smooth Muscle. 545 



ABBREVIATIONS. 



1. m., lougitmlinal muscle coat. 



e. lu., circular muscle coat. 



c. w., contraction wave. 



c. n., contraction node. 



i. s., internodal segnient. 



i. c, interstitial connective tissue. 



c. {., collagenous fibers.^ 



e. f., elastic fibers. 



g. p., granular protoplasm, 

 p. s., protoplasmic syncytium. 

 c. mf., coarse niyofibrillje. 



f. mf., fine niyofibrillfe. 



t. mf., tbickeuetl myofibril Ine. 



nu., nucleus. 



r. nu., nucleus of resting muscle. 



cb. f., cbromatin festoon in contracted nucleus. 



All figures were drawn by means of a camera lucida. Tbe following 

 microscopic lenses were used. Zeiss achromatic D and apochromatic 2 mm. 

 1 :30 objectives with compensating oculars 4, 8 and 12 ; Leitz Vjo in. oil 

 immersion and Bausch and Lomb V^o in. oil Inunersion objectives with 1 in. 

 ocular. 



