220 MUSCULAR SYSTEM. 



muscles. Now, as long as this vital voluntary power is 

 in action, the textural contractility of the muscle is over- 

 come. But as soon as this vital force ceases to act, the 

 contractility of texture restores the limb to the medium or 

 resting point. When the will acts on the muscles, vital 

 forces are in play; when it ceases, contractility of texture 

 restores the limb to rest. 



Q. What is the cause of the extended limbs in typhus 

 fever in its last stages? 



A. It does not proceed from increased action of the ex- 

 tensors, but from a loss of textural contractility in the 

 flexors. 



Q. Can you give instances of this contractility of tex- 

 ture in action ? 



*/#. When a muscle is cut through, the fibres retract 

 considerably; when a woman is delivered, the abdominal 

 muscles return to a natural state by means of this contrac- 

 tility of texture. Repeated distention diminishes this 

 textural property. 



Q. How does long-continued ascites, affect respiration 

 even after the water has been removed? 



*ft. Long-continued pressure of the water on the dia- 

 phragm diminishes its contractile power, and dyspnoea 

 continues; so it is after repeated pregnancy. 



Q. To what is this contractility of texture relative? 



#. It is in proportion to the length of the fibres of the 

 muscle ; it is greatest in the longest muscles, and for this 

 reason in amputation the superficial muscles contract the 

 most. In sleep the legs are most contracted. 



Q. There is another obvious difference between this 

 contractility of texture and the vital properties, what is it? 



