MUSCULAR TISSUE. 8 1 



although we never could convince ourselves of this. The 

 middle layer of the vessels, especially of the arteries, contains 

 smooth muscle. Small bundles of the same occur in the co- 

 rium ; thus, in the hair-sacs, arrectores pilorum, furthermore, 

 from the surface of the corium to the subcutaneous cellular 

 tissue (J. Neumann), then, more connectedly, on the nipple 

 and the areola, and especially in the so-called tunica dartos 

 of the testicle. The walls of the gall-bladder are also muscu- 

 lar. In the urinary apparatus, in the calices, and pelvis of 

 the kidneys, the ureters, and the bladder our tissue acquires 

 a greater development. The male generative apparatus is 

 likewise abundantly provided with smooth muscular sub- 

 stance ; still more so that of the female. Even the ovary, 

 according to our view, harbors this tissue. It forms con- 

 nected layers in the oviducts. Altogether the most massive 

 collection of the tissue is met with in the womb. During 

 pregnancy it acquires a still greater increase. The lymphatic 

 glands, the eye (sphincter and dilator pupillae, choroid, the 

 ciliary, orbital, and palpebral muscles) also have smooth 

 muscles. 



We meet with transversely striated tissue in all the muscles 

 of the head, trunk, and limbs, the auricle, the external mus- 

 cles of the eye, in the tongue, the pharynx, the upper por- 

 tions of the oesophagus, the genitals, the termination of the 

 rectum. Our tissue likewise forms the diaphragm and, modi- 

 fied, the heart. 



As element (Fig. 75, a) we recognize in man at once a long, 

 unramified, cylindrical, filamentous element of O.oi 13, 0.0187 

 to 0.0563 mm., transverse diameter. This is the muscular 

 filament, the muscular fibre, or, as is badly said, the primi- 

 tive bundle. 



Here, however, we at once notice a peculiarly complicated 

 texture. 



We meet with an envelope and contractile contents ; the 



sarcolemma and sarcous element. The former, closely applied 



to the living muscular filament as a constant companion, may, 



in death, become elevated in a vesicular manner by the 



4* 



