'26.1 PHILOSOPHICAL TRANSACTTONS. [ANNO i6()8. 



must necessarily bend and curve that joint. But for the strengthening the 

 whole, there was observed four muscles to arise from the os sacrum, which ran 

 the whole length of the tail ; two on the upper side, and two on the under ; 

 sending each a tendon to each internode or vertebra. So that when the skin 

 was stripped off, the external parts of these muscles seemed to have tendinous 

 expansions over them, the whole length of the tail, and to be almost covered 

 by them ; which must needs very much contribute to add strength to the tail ; 

 besides what may be the effect of their insertion of tendons into each joint, or 

 vertebra, in curling and unbending the tail. 



To the vertebrae of the thorax are fastened the ribs, and there are 13 on 

 each side. The 7 foremost are more perfectly articulated with the sternum ; 

 the 6 succeeding may be reckoned, in some sense, cost^ nothae : for though 

 they are long, and, as they proceed from the vertebrae, are inclined backwards, 

 towards the hinder legs ; yet afterwards they are reflected forwards towards the 

 sternum, or cartilago scutiformis. And though in man, and other animals, 

 that part of the ribs that is fastened to the os pectoris, or sternum, be usually 

 cartilaginous, yet, in this subject, it is all bony throughout. There was how- 

 ever this difference, that the ribs looked redder, by reason of their blood- 

 vessels, and this part was whiter; so that it may well pass for a bony cartilage, 

 as often cartilages become bony. The first rib was only an inch in length, and 

 its bony cartilage 4- of an inch : hence gradually the ribs increase in length ; 

 for the 7th rib was 3 inches long ; and its cartilage 1^ inch. The last 4 of the 

 costae nothae gradually lessen again in length ; for the last rib of all was only 

 ]i inch long ; and its cartilage did not run home to the os pectoris, or sternum, 

 though the 1st, 2d, and 3d of the costae nothae did. The sternum consisted 

 of 7 bones, according to the number of the fore-ribs, that are fastened to 

 them. At the beginning of the sternum, there jetted out a sharp bony car- 

 tilage, which, from its figure, I call cartilago ensiformis ; and here was fas- 

 tened one extremity of the claviculae ; at the end of the sternum, towards the 

 belly, there was a broad, round cartilage, which therefore I call cartilago 

 scutiformis. 



There were two claviculae, or collar-bones, each li inch, having one ex- 

 tremity fastened to the first bone of the sternum, or the cartilago ensiformis; 

 and the other to the spine of the scapula, near its conjunction to the os humeri. 

 By means of this bone, it can more advantageously bring its forc-fcet to its 

 mouth, as it must do wlien it feeds itself, like the nionkey-kintl, which have 

 claviculae as men have The scapula, or shoulder-blatic, was about 2 inches 

 long, about 1-^ inch broad ; its spine, though thin, yet the nearer it approached 

 the shoulder, it grew larger and flatter. Into the sinus of the neck of the 



