DISSECTING MANUAL. 



body, or demi-facet on its upper edge, for the tenth rib; the 

 facet on its transverse process is small, or absent. The eleventh 

 has a single whole facet, for the eleventh rib, on the outer side 

 of the pedicle; the transverse processes are short and without 

 facets. The twelfth has a single costal facet on the pedicle ; the 

 transverse process has no facet and ends in three tubercles, ex- 

 ternal, superior, and inferior; the inferior articular processes 

 look outward (those of the eleventh may do so) . [81] 



Sternum. The breastbone is flattened; it is broadest 

 above, narrows opposite the second costal cartilage, then ex- 

 pands down to the fifth costal cartilage, and then tapers rap- 

 idly. It consists of three parts, viz. : Manubrium (upper part) . 

 This is triangular and usually separate. The anterior surface 

 is saddle-shaped; the posterior is smoother and concave. The 

 thick upper border prasents a slight mesial notch (incisura 

 jugularis) between lateral hollowings for the clavicular facets. 

 Each lateral border presents, just below the clavicular facet, 

 an excavation for the first costal cartilage; and below this a 

 sharp border which slopes inward and has, at its lower end, a 

 demi-facet for the second costal cartilage. The lower end is 

 flat and joins the gladiolus. [94] 



Body or Gladiolus (middle part). The anterior surface is 

 slightly convex vertically and concave transversely; it has 

 three faint transverse ridges indicating the fusion of four 

 primitive segments. The posterior surface is slightly concave 

 vertically and has similar transverse lines. The upper border 

 joins the manubrium (sternal angle) and has at each end an 

 excavated demi-facet for the second costal cartilage. The 

 lower border is curved, joins the xiphoid cartilage mesially, 

 and on each side is pitted for the sixth and part of the seventh 

 costal cartilages. The thick lateral borders have, at the ends 

 of the transverse lines, U-shaped hollows, with projecting 

 edges, for the third, fourth, and fifth costal cartilages. [95] 



Ensiform or Xiphi-Sternum (lower part). This is cartilagi- 

 nous, has a bony core, and is pointed, of varied shape, and 



[1081 



