Chap. VIII.] 



CHAPTER VIII. 



NON-STRIPED MUSCULAR TISSUE. 



78. THIS tissue consists of nucleated cells, which, 

 unlike amceboid cells, are contractile in one definite 

 direction, becoming shorter and thicker during con- 

 traction. 



The cells are elongated, spindle-shaped, or band-like 

 (Fig. 3 8 A), and drawn out at each extremity into a longer 

 or shorter, generally single but occasionally branched, 

 tapering process. Each cell includes an oval nucleus, 



Fig. 38A. Non-striped Muscular Fibres, isolated. 



The cross-markings indicate corrugations of the elastic sheath of the individual 

 fibres. (Atlas.) 



which is flattened if the cell it belongs to is flattened. 

 The cell-substance is a pale homogeneous-looking or 

 finally and longitudinally striated substance. 



During extreme contraction the nucleus may 

 become more or less plicated, so that its outline be- 

 comes wavy or zig-zag. 



It has been shown (Klein) in certain preparations 

 e.g., the non-striped muscle cells of the mesentery of 

 the newt that each muscle cell consists of a delicate 



