11 EPISTERNUM OF MAN 35 
pair of similar bones in the Hamster.! It is possible that these 
are to be referred to the same category. It has also been 
el. 
Fie. 24.—Episternal 
vestiges in Man. 
cl, Clavicle, sawn 
through ; es, ‘“epi- 
~¢ sternum”  (sterno- 
clavicular cartilage) ; 
U,interclavicular 
ligament; 7’, costo- 
clavicular ligament ; 
m.s, Manubrium 
sterni ; 0.8,  ossa 
suprasternalia ; 7.¢, 
first’ -nibi) “st. ‘ster- 
num. (From Wie- 
dersheim’s Structure 
of Man.) 
suggested that these supposed episternal rudiments are the 
vestiges of a pair of cervical ribs. 
The Pectoral Girdle—The skeleton by which the fore-limb 
is connected with the trunk is known as the Pectoral Girdle. 
The main part of this girdle is formed by the large scapula, or 
blade-bone as it is often termed. The coracoidal elements will be 
dealt with later. The scapula is not firmly connected with the 
backbone; it is attached merely by muscles, thus presenting a 
vreat difference from the corresponding pelvic girdle. The reason 
for this difference is not easy to understand. On the one hand 
it may be pointed out that in all running animals at any rate 
there is a greater need for the fixation in a particularly firm way 
of the hind-limbs; but, again, in the climbing creatures both 
limbs would, one might suppose, be bettered by a firm fixation. It 
must be remembered, however, that in the latter case the same 
result is at least partly brought about by a well-developed clavicle, 
which fixes the girdle to the sternum and so to the vertebral 
column by means of the ribs. 
Broadly speaking, too, the fore-limbs require a greater freedom 
and variety of movement than the hind-limbs, which are supports 
1 Vergl, Anat. der Wirbelth. Leipzig, 1898, p. 497. 
