OP LIFE. 33 



%/?. A muscle will exemplify this best. Thus, 1st, cere- 

 bral impulse conveyed through the nerves, occasions a con- 

 tractility; this is animal contractility, and involuntary; 

 2d, on the application of a strong stimulant, there will be 

 a muscular motion, which is sensible organic contracti- 

 lity, or irritability; this is involuntary; 3dly, a penetra- 

 tion of all the parts of the muscle by its nutritive fluids, 

 developes a movement of oscillation, which is insensible 

 organic contractility or tonicity, and this is involuntary; 

 4thly, cut across a muscle and its fibres retract; this is the 

 contractility of texture; lastly, various organs possess 

 one or more of these forms of contractility. 



Q. What form of contractility is possessed by all living 

 parts? 



ft. Insensible organic contractility or tonicity. 



Q. Name that contractility which is the attribute of 

 all parts, living or dead? 



A. All tissues, whether living or dead, possess contrac- 

 tility of texture. 



Q. Can you give a tabular recapitulation of. the pro- 

 perties of living bodies? 



#. The general division is into vital and textural pro- 

 perties. 



Vital Properties. 



A. Sensibility the faculty which an organ feels. 



a. *ftnimal sensibility ; in which the sensation is felt 

 by the organ, and conveyed to the brain. 



b. Organic sensibility ; in which the organ feels, but 

 the sensation is not conveyed to the brain. 



B. Contractility the faculty by which motion volun- 

 tary or involuntary takes place. 



a. Animal contractility voluntary. 

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