48 THE STRUCTURE OF MAN 
it, must not be confounded with the above-described skeletal 
structures, which are entirely incorporated into the manubrium. 
These “ ossa suprasternalia ” (0.s., Fig. 30) may be derivatives of 
the episternal apparatus, as Gegenbaur has for years insisted, and 
probably of the central portion of the episternum. The lateral 
portions of this structure are usually homologised with the inter- 
articular cartilages that lie between the sternum and the ventral 
extremities of the clavicles (¢.s., Fig. 30). [There is, however, 
cd. 
; 0.8, 
eo €.S. 
ANS 
\\ 
~ ye ‘ 
f \ = a ie ‘ _—/ 
SQ SS 
WY \\\ \\ CSS ye Y 
\ \\ y < a 
1.8. 
Fic. 30.—EPISTERNAL VESTIGES IN MAN. 
é.s., ‘“episternum” (sterno-clavicular cartilage) ; 0.s., ossa suprasternalia ; cl., clavicle, 
sawn through ; /’., inter-clavicular ligament ; 2’., costo-clavicular ligament ; m.s., 
manubriumjsterni ; s¢., sternum ; 7.c., first rib. 
still considerable uncertainty about this ; especially as Carwardine 
has recently shown? that the ligaments in which the “ ossa supra- 
sternalia ” lie embedded when free, may or may not be continuous 
with an “inter-clavicular ligament” which, by its T-shaped 
character and detailed relationships, may suggest the inter-clavicle 
(episternum) of Monotremes and Reptiles. ] 
THE SKULL 
In all Vertebrates the skull may be divided into two 
principal portions, the cranial and the facial. The cranial 
portion, or brain case, encloses the anterior part of the central 
nervous system, and is intimately associated with the higher 
1 Jour. Anat. and Phys., vol. xxvii. p. 282. 
