34 2 ALFRED G. MAYER. 



neuro-muscular system, and at first subdues and afterwards stimu- 

 lates the movement of cilia. Ca is a depressant for nerves and 

 muscles but a weak stimulant for cilia. NH 4 C1 is a primary 

 stimulant for muscles but soon produces depression, while upon 

 cilia its effect is the reverse, a primary cessation of movement 

 being followed by recovery. The CO 2 ion inhibits muscular 

 activity, while in weak concentration it produces a primary de- 

 pression of cilia followed by a recovery of movement. 



