MUSCLES. 475 



which most are imbedded ; the lymphatic vapour around each ; 

 and, above all, by the conformation of the skeleton, chiefly in 

 regard to apophyses, condyles, and articulations ; nay, even 

 whole bones, v. c. the patella, the pisiform of the carpus, and the 

 sesamoid bones m , are destined solely to facilitate the actions of 

 certain muscles. 



" In. this mode is compensated, or, at least, diminished, that 

 inevitable loss of power which necessarily takes place from the 

 conformation and stature of the whole system, as, from the acute 

 angle at which some muscles are inserted, or the proximity of 

 their insertion to the centre of motion, much of that power is lost 

 which would have existed, if their insertion had been more remote 

 or at a more obtuse angle." 



" The human body, possessing about 450 voluntary muscles, or 

 upwards, according to sexual or individual variety, is thus fur- 

 nished 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 

 that, like the perfection of the bones, takes place at manhood ; 

 and partly by habit and practice, the power pf the former of 

 which in affording strength and agility to the muscles is demon- 

 strated in rope-dancers, leapers, runners, wrestlers, porters, sa- 

 vages, and the examples of ancient nations." 



When a muscle has ended its contraction, antagonising muscles, 

 the elasticity or gravity of parts, solid, fluid, or gaseous contents 

 pushed forwards from the higher portions of the canal, &c. &c., 

 are enabled, through its diminished resistance, to elongate it. The 

 mere cessation, however, of its contraction must be supposed to 

 lengthen a muscle. For if, while under the exertion of a force 

 drawing it together it is of a given length, this cannot remain the 

 same when this force is no longer exerted. But any great elong- 

 ation of it is accomplished by antagonising powers. When the 

 heart has contracted, its relaxation is said, as we have seen, to be 



m " Hence, of all animals which I have dissected, the mole is supplied with 

 the most remarkable apparatus of sesamoid bones ; its anterior palmated feet, 

 with which it digs, have many of these bones, which greatly facilitate the action 

 of the brachial muscles." 



n " Gilb. Blane, On Muscular Motion, p. 51." 



" I have treated on this point at large, in the Medic. Biblioth. vol. ii. 

 p. 407." 



