In general these two last are inherent in every kind of organ, the two first belonging to some in particular only; hence for the general character of living parts we must choose the insensible organic contractility or tonicity, and for the character of all organized parts whatsoever, whether living or dead, the contractility of texture.[38] We shall farther remark, that this last in the same way as its corresponding extensibility possesses them, has its different degrees, its scale of intensity, the skin and the cellular substance on the one hand, the tendons, the aponeuroses, and the bones on the other, forming the extremes of this scale. From all that has been said, it is easy to perceive, that in the contractility of every organ there are two things to be considered, namely the contractility, or the faculty, and the cause, which puts it in action. The contractility is always the same, belongs to the organ, is inherent in it, but the cause which determines its exercise may be various. VIII. _Recapitulation of the properties of living bodies._ A recapitulation of these properties may be seen in the following table: _Properties._ _Classes._ _Genera._ _Species._ _Varieties._ { { 1st Animal { 1st Sensibility-- { { { 2d Organic 1st Vital-- { { { 1st Animal { 2d Contractility--{ { 1st Sensible { { 2d Organic--{ { 2d Insensible { 1st Extensibility 2d of Texture-- { { 2d Contractility I have not inserted in this table that modification of motion, which takes place in the iris, the corpora cavernosa, &c. a motion, which precedes the influx of the blood, and which is not in such way occasioned, neither have I mentioned the dilatation of the heart,[39] and in a word that species of active and vital excitability, of which some parts appear to be susceptible, and my reason for this neglect, although I recognise the reality of the modification, is my want of clear and precise ideas on the subject. From the properties, which I have now explained, are derived all the functions, all the phenomena, which are exemplified in the living œconomy. There is not one, which may not be traced to them after a strict analysis, in the same manner as in the phenomena of physics we recur to the properties of attraction, elasticity, &c.