STRUCTURAL CHARACTERS OF ANIMAL ORGANISMS. 



51 



of animal life. They are nearly related in their origin, or even 

 spring from the same primitive tissue. In fact, as has already 



FIG. 23. 



Fir. 22. Cells of smooth muscle tissue from the intestinal tract of rabbit. (Ranvier.) 

 A and B. Muscle cells in which differentiation of the protoplasm can be well seen. 

 (Schiifer.) 



FIG. 23. Two fibres of striated muscle, in which the contractile substance (TO) has been 

 ruptured and separated from the sarcolemma (a) and (j) ; (p) space under sarcolemma. 

 (Rmvier.) 



