510 
MR. OSLER’S OBSERVATIONS ON THE ANATOMY 
spire, mantle, and branchiae, and laid open in a direction corresponding- with 
the longitudinal axis of the body. The trunk is displayed in situ, with its 
extremity issuing from the containing tube, and resting at the aperture of the 
mouth. The annular muscles are seen on the containing tube, the last of the 
series being distinguished from all the others by its size and colour. The 
origins of some of the muscles of the trunk are perceived on either side. 
In fig. 15. the trunk is projected to its full extent. The curvature and un¬ 
equal thickness of the extended portion are quite characteristic. The multi¬ 
tude of muscles which arise from either side of the body, and especially from 
the right side, are seen entering the extremity of the trunk, while the oesopha¬ 
gus passes out from underneath them. 
Removing the trunk from the body, and opening it down the side, we shall 
display the upper part of the tongue, with its muscles, as in fig. 16. The 
oesophagus is thrown with the divided tube to the left side, and the tortuous 
salivary ducts are seen passing along its under surface to the pharynx. Be¬ 
hind is the great annular muscle, d, with the mass of muscles which run for¬ 
ward to be inserted along the tube and into the tongue. The muscles where 
they arise from the body, as well as all those inserted into the tube, have the 
pearly bluish tint common to the muscular fibre of fishes; but the great annular 
muscle, and all inserted directly into the tongue, are of a red colour. Ante¬ 
riorly at e, is the funnel-shaped muscle which projects the active portion of 
the tongue. The base is marked a, one of its crura b , and the muscular bands 
which connect its opposite margins c. Under these transverse bands, and 
issuing from behind them, is the sheath of the tongue, tortuous, and with a 
considerable muscle attached to its extremity; while beneath it, and within 
the crus of the base, are the long muscles which are inserted into it. The 
thin flat muscle h, given off on either side from near the extremity of the tube, 
and taking a somewhat oblique direction backward to be inserted into the 
base, probably assists in projecting and rotating the tongue. 
Fig. 17, in which the tube is opened along its under part, displays many of 
the muscles represented in the preceding. They are distinguished by the same 
letters. The posterior part of the tube is contracted into annular folds by the 
corresponding muscles; and anteriorly, the tongue, having been stretched 
over the cartilaginous points of the base, is doubled back, its extremity being 
