MUSCULAR ACTION 



375 



of the toes and fingers to the scalp. Unstriated, smooth, or "involuntary" 

 (reflex or " vegetative") muscle is present throughout the entire vascular 

 system and the lymphatic vessels, placed in almost exery portion of the 

 body; in the wall of the whole alimentary canal from the pharynx to the 

 anus; in the gall-bladder and common bile-duct; in the trachea, bronchi, 

 and bronchioles; in the kidneys, ureters, bladder, and urethra; in the 

 spleen; in the adrenals; in many gland-ducts and mucous membranes; in 



FIG. 227 



The universality of muscle-tissue. When one mentally combines the fragmentary views shown 

 here and extends them all over the body it is obvious that muscle is essentially a universal 

 contractile fabric of the organism. Functionally it is not merely a collection of separate organs. 



the skin ; in the sweat-glands ; in the mamma, mammilla, ovaries, uterus, 

 Fallopian tubes, vagina, epididymis, vas deferens, prostate, tunica 

 dartos, seminal vesicles; in the iris; and probably in still other places. 

 The heart is made largely of a sort of muscle partaking of the nature 

 apparently of both these other sorts of muscle. Van Beneden claims 

 that the rays of the amphiaster-spindle in mitosis are contractile in nature, 



