The Digestive System 
173 
even in this anterior region are not everywhere 
present; possibly they are arranged in bands, but 
the material at hand was not suf- 
ficient to determine this. As was 
noted above, cilia are wanting in the 
posterior region. 
The only differences noted in the 
anterior region of the cesophagus 
between the feeding and the hiber- 
nating conditions are in the muscu- 
laris mucosa and the epithelium. 
As was noted above, the muscularis 
mucosa is practically absent in the 
hibernating stage, being represented 
only byafewsmall, scattered bundles 
of longitudinal muscle fibers; while 
in the feeding stage there is a narrow 
but fairly distinct layer to represent 
the muscularis mucosa. 
The difference in the appearance 
of the epithelium is not striking. 
The nuclei are somewhat larger in 
the feeding stage and, instead of 
being crowded into a basal and a 
median zone, as noted in the hi- 
Fic. 44. The 
epithelium of the 
anterior region 
of the cesophagus. 
of the feeding 
animal, under 
high magnifica- 
tion. 
bernating conditions, they form a dense basal 
zone, but show no indication of medial zone. From 
the dense basal zone the nuclei become more scat- 
tered towards the free surface and are rarely found 
closer to the surface than is shown in Figure 44. 
