382 ELDON W. SANFORD 
of the intima. Such appearances disprove beyond question 
Ramme’s contention that the muscles terminate in the inner 
surface of the intima. The fibers run not only to the intima, 
but through it (as tendons) to its outer surface and to the needle 
bases (fig. 11). 
The needles are quite considerable in size, being 0.10 mm. to 
0.15 mm. in length. Ramme has said that their extreme min- 
uteness in comparison to the muscle structures precludes any 
mutual action, yet an examination of my figures reveals that the 
needles are much larger than the muscle fibrillae and tendons, 
and so connected with them that their movement by the tendons 
seems probable. The purpose of this movement is difficult to 
explain, but their position and arrangement suggest that proba- 
bly they aid in moving food along through the gizzard toward 
the stomach, as Petrunkevitch suggested. 
The region between the cushions and the narrow stomach 
passage is occupied by many folds of various sizes (figs. 7, 15, 
16). These are all provided with spines, many of them being 
so inserted that they can lie flat on the surface. Several of 
the folds usually lie closely together, blocking entirely or par- 
tially the passage into the stomach. This arrangement enables 
them to hold back food, and I believe that in these folds the 
sphincter action of the gizzard is largely to be found. It is cer- 
tain that the gizzard does act as a very efficient sphincter, hold- 
ing back fluids for three days. We have seen that neither the 
teeth nor the cushions make a tight joint, so the only possible 
position for efficient retention of food is this rear part of the giz- 
zard. Moreover, this is a logical position for a sphincter,, for 
it is only necessary to protect the small opening into the stomach, 
the narrowest section of the whole alimentary canal; while in 
the more anterior gizzard, a much broader cavity would neces- 
sarily be closed by any structure acting as a sphincter. The 
arrangement of the folds is shown in cross section in figure 16, 
and in longitudinal section in figure 15. In both cases it is seen 
that the folds are surrounded by a considerable muscle sphincter, 
which brings about the appression of the folds by its contrac- 
tion. The sphincter may be thicker than that which surrounds 
