So6 ESSAYS AND OBSERVATIONS 



ribs is large enough to allow the lower 

 lib to approach i'o much to the one above 

 it, as ro do more than compenfate for the 

 elongation ot the hypotheneufe of the an- 

 gle FEI, z. e the internal intercoftal is 

 only to be found farther forward than 

 the angles of the ribs. 



Near to the flernum, the cartilages 

 cannot be brought nearer ; and therefore, 

 •when they are raifed up, HL, the fibres 

 of the internal intercoilal may be fliorten- 

 ed, becauf^ the angle HMI. is made lefs : 

 Bat, if there were fibres of the external 

 intercoftal here, as GM, they would be 

 made longer, becaufe the angle GHM is 

 enlarged by raiung the ribs ; and there- 

 fore no external intercoftal mufcles are 

 placed at this forepart of the thorax. 



/. Ri . 



