94 



CHORDATE ANATOMY 



striations extending continuously across the cell. Muscle cells of this 

 sort are called striated. Uninucleate striated fibers occur in the heart 

 of some moUusks. In arthropods, especially insects, striated fibers 



Fig. 88. — Striated muscle; human. Above, in longitudinal section, showing small 

 portions of several fibers; below, section transverse to the length of the fibers. Nuclei 

 lie at the surface of the fiber. (From Bremer, "Text-book of Histology.") 



attain great length, are multinucleate, and exhibit a complex system of 

 transverse striations. 



Vertebrates possess both striated and unstriated (or "smooth") 

 muscle (Fig. 87). In general, the muscle of the bodv-wall is striated and 



