196 OF MUSCULAR MOTfON. 



or upwards, according to sexual or individual variety, 

 is thus furnished with a double advantage, — with an 

 extreme agility of motion in particular parts and 

 throughout the whole, and with a surprising degree of 

 strength and endurance of labour. Both these are 

 accomplished partly by the perfection of the muscles, 

 which, like the perfection of ossification, takes place 

 at manhood; and partly by habit and practice, the 

 former of which in affording strength and agility to the 

 muscles, is demonstrated in rope-dancers, leapers, 

 runners, wrestlers, porters, savages, and the examples 

 of ancient nations.* 



NOTES. 



(A) Mr. Bauer discovers muscular fibres to be chains of 

 globules ; f and it is suggested tliat they may be constructed by 

 the globules of fibrine arranging themselves in lines. 



(B) Irritability is the power of contracting upon the appli- 

 cation of a stimulus, and ceases with life. It comprehends 

 animal and organic contractility, (See Note to Sect. VI.) and we 

 must suppose the lacteals, vessels of glands, gall bladder, and 

 dartos to be possessed of it : the uterus will hereafter be shewn 

 I>ositively to have muscular fibres, and their existence will be 

 rendered probable in the corpora cavernosa of the human penis. X 



(C) See Note F. Sect. XII. 



(D) This paralysis does not show the irritability of the 



• I have treated on this point at large, in the Medic. Ulblinth. Vol. ii. p, 407.- 

 f Phil. Tram. 1818. 



♦ Mr. Shaw has written a very excellent paper against the muscularity of 

 the urethra. Med. Chir. Tram. Vol. X. 



