184 



PHYSIOLOGY 



Other muscles in the frog used for particular purposes are the mylohyoid and the 

 dorsocutaneous muscles. The mylohyoid muscle of the frog, which lies on the ventral 

 surface of the tongue, has the advantage that its fibres lie in close contact with a 



Tib. ant. loug. 



Tendo Achillis 



FIG. 41. Muscles of hinder extremity of frog. (After ECKER.) 



lymph-space occupying the centre of the tongue. If any drug be injected into this 

 lymph-space it acts with extreme rapidity on the muscle fibres, so that the tongue- 

 preparation of the frog is a useful one for the study of the action of different substances 

 on muscle fibres. 



