THE CONTRACTILE TISSUES. 



That contractility, which is a fundamental property in some 

 degree of all protoplasm, becoming pronounced and definite, 

 giving rise to movements the character of which can be pre- 

 dicted with certainty once the form of the tissue is known, finds 

 its highest manifestation in muscular tissue. 



Very hriefly, this tissue is made up of cells which may be 

 either elongated, fusiform, nucleated, finally striated lengthwise, 



Fig. 1S4. 



Fig. 165. 



Fig. 154.— Muscular fibers from the urinary bladder of the human subject. 1 x 200- 

 (Sappcy.) 1, 1, 1, nuclei; 2, 2, 2, borders of some of the fibers; 3, 3, isolated fibers; 

 4, 4, two fibers joined together at 5. 



Fig. 155.— Muscular fibers from the aorta of the calf. 1 x 200. (Sappey.) 1, 1, fibers 

 joined with each other; 2, 2, 2, isolated fibers. 



but non-striped transversely, united by a homogeneous cement 

 substance, the whole constituting non-striped or involuntary 



