98 r.RDOKLVN" INSTITl-TK MUSKl.M. SCIENCE BULLETIN 2. 4. 
and the (Vsopliai^iis are in front of the neck, the larg-e (:esoi)ha- 
gus being lietween the two and the trachea in a(h-ance of it. 
These two tn1»es are in the middle hne for a >hort distance 
lielow the hyoidean ai)])aralus, l)ut tliev gradually jiass to the 
right side of the neck as ilicy descend, and onlv become sub- 
mechan again as they. '~ide b\ side, enter the chest lietween the 
cla\-icnlar limbs. At this stage, (/// flic rii!!:;s of flic fi-achca 
are in elementary cartilage, and the exjiosed jiart of the tul)e 
is c\lindrical in form lietween its extremities. 
Mail}- of the siifcrficial muscles of the head, neck and trunk 
are \-isilile and easily m.ade out. .\tlention is invited to two or 
three of the most ])rominenl ones in h'ig. j, as the ;^lufcus 
friiiins (i^p): the Icwi'tilor caiuliC (Ic): the pcroiiciis loiit^^iis 
{N). and the ohlicimis cslcriiiis ahdcimuus (o c a). 
( )n the side of the body, immediately anterior to the knee 
and in contact with its su[)erhcial structures, there is f|uite a 
sizealile mass of adipose fissiic: it is of an irregular form, 
transversely compressed, and rests, in either case, on the side 
of the chest. 
The rudimentary retrices, wliich at this stage appear as 
tine little white s]>icu]a-. are twelve (IJ) in number; the six 
of the right side are well ^cen in I'ig. 2. 
\'er_\- little osseous maleri.al has as vet de\-e!o])cd in the 
bone-, of cither the pectoral or the pelvic limbs, and these 
structures are in a \ery elementar\- condition. 
The liyoiilcan apparatus is entireh' in cartilage, in so far as 
its skeletal ]>arts are concerned, and the same may be saitl of 
the cordate-shaiied superior lai-yn.v. which lies between its 
backward-extending limbs. The riiiia i^lnffidis li;is a length 
of two millimeters, or somewhat longer th.an that of the com- 
mon opening of the liiisfacJiiau tubes, which is to be seen at 
its usual site in the riiaiaei-cciu-aeidic at the l)a-is cranii. 
.Xine millimeters in front of the luistachian aperture and in 
the median line, is to be obser\ed the posterior uares. another 
loULiiludinal slit-like o])ening of a ^ize about e(|ual to the tirsl- 
nanied one. 
b".\-en at this yer\- earl\- stage of growth of the indi\-idual. 
the selcrofal plafcle'ts of the e\e are easily to be m.ade out. and 
