bb OF THE MUSCLES. 



then was to be done ? This, we find, is done. The de- 

 scending tendon, when it is got low enough, is passed 

 through a loop, or ring, or pulley, in the os-hyoides, and 

 then made to ascend ; and, having thus changed its line of 

 direction, is inserted into the inner part of the chin ; by 

 which device, viz. the turn at the loop, the action of the 

 muscle (which in all muscles is contraction) that before 

 would have pulled the jaw up, now as necessarily draws it 

 down. " The mouth," saith Heister, " is opened by means 

 of this trochlea in a most wonderful and elegant manner." 



IL What contrivance can be more mechanical than 

 the following, viz. a slit in one tendon to let another ten- 

 don pass through it ? This structure is found in the ten- 

 dons which move the toes and fingers. The long tendon, 

 as it is called, in the foot, v/hich bends the first joint of the 

 toe, passes iliroiigh the short tendon which bends the sec- 

 ond joint ; which course allows to the sinew more liberty 

 and a more commodious action than it would otherwise 

 have been capable of exerting.* (PI. XVI. fig. 1, 2.) There 

 is nothing, I believe, in a silk or cotton-mill : in the belts, 

 or straps, or ropes, by which motion is communicated from 

 one part of the machine to another, that is more artificial, 

 oi' more evidently so, than ihis perforation. 



III. The next circumstance which I shall mention, un- 

 der this head of muscular arrangement, is so decisive a 

 mark of intention, that it always appeared to me, to super- 

 sede, in some measure, the necessity of seeking for any 

 other observation upon the subject ; and that circumstance 

 is, the tendons, which pass from the leg to the foot being 

 bound bown by a ligament at the ankle. (Pi. XVI. fig. 3.) 

 The foot is placed at a considerable angle with the leg. 

 It is manifest, therefore, that flexible strings, passing along 

 the interior of the angle, if left to themselves, would, when 

 stretched, start from it. The obvious preventive is to tie 

 them down, And this is done in fact. Across the instep, 

 or rather just above it, the anatomist finds a strong liga- 

 ment ; under which the tendons pass to the foot. The ef- 

 fect of the ligament as a bandage, can be made evident to 

 the senses ; for if it be cut, the tendons start up. The 

 simplicity, yet the clearness of this contrivance, its exact 

 resemblance to established resources of art, place it amongst 

 the most indubitable manifestations, of design with which 

 we are acquainted. 



* Ches, Anat, p. 94, 119, 



