PLATE IX. 



Parts of the sternum and sternal ribs, half the natural size. 



Fig. I. Tlie successive sternal bones are indicated by reman numerals, 

 , I. to VI., about two-thirds of the sternum being probably here exhibited 

 from the internal or posterior aspect. 



a. Anterior costal articular surface of the manubrium. 



h. Contracted part supporting the posterior costal surfaces. 



Fig. 2. External or anterior surface of the manubrium sterni. 

 c. Posterior costal surfaces. 



Fig. 3. External or anterior view of the fourth and fifth sternal bones, 

 showing the complex articulations of the extremities of the ossified 

 sternal ribs therewith : one of these ribs is dislocated on the left side 

 to show the four distinct surfaces, two separate and two approximate, 

 on the contiguous angles of the anterior and posterior divisions of the 

 conjoined sternal bones. 



Fig. 4. A side-view of the fourth and fifth sternal bones. 



a. Anterior costal surface of the outer tubercle or division. 

 a. Posterior costal surface of the outer tubercle or division. 

 h. Anterior costal surface of the inner plate or division. 



h'. Posterior costal surface of the inner plate or division. 



Fig. .5. Sternal end of the ossified sternal rib detached from its articulation 

 with the preceding sternal bones. 

 0. Lower division of terminal articular surface, which joins with the 



surface a in tig. 4. 

 a'. Upper division of terminal articular surface, which joins with the 

 surface a! in fig. 4. 



b. Lower division of subterminal articular surface, which joins with 

 h in fig. 4. 



h'. Upper division of subterminal articular surface, which joins with 

 V in fig. 4. 



