S. YOSCHIDA 209 
appearance to be split so as to i^ivc rise to the outer loosened layer. In the 
basal part the nuclei are crowded because here active cell-multiplication is 
taking place. 
From the facts above pointed out, it is true that the cardiac sac which 
occupies in volume about one half of the gastric pouch cannot be distinguished 
histologically from the Oesophagus, it represents a part of the Oesophagus. 
VVe see, therefore, that the results arrived at by the microscopical examination 
perfectly confirm my conclusion above given according to which the cardiac 
sac is nothing but a [lart of the Oesophagus strongly bulging out and serv- 
ing as a temporary strage place for food. If this assumption is valid, the 
boundary ridge itse'f is to be included in the eosophagal parts ; for it is by no 
means distinguishable from the cardiac sac as far as the microscopical struc- 
ture is concerned. 
Let us now turn to the corresponding structures in the domestic rabbit, 
which have been almost satisfactorily made known by previous authors. In 
the first place, the Gastric pouch is simple, being entirely occupied by the 
ventricular part ; there is no appendage existing which corresponds to the 
cardiac sac of the rat. As obvious, the left part of the gastric pouch is 
protruding upwards, apparently looking like a cardiac sac, but it is a part of 
the ventricular section so raised. Consequently the boundary ridge shifts to 
the so-called Cardia at the base of the Oesophagus, describing a small circle at 
the height of the Gastric pouch, instead of a large ellipse at the middle trans- 
verse vertical j^lane of the corresponding pouch in the rat. As a comparison 
of (PI. X. Fig. 2) which represents a diagramatic longitudinal section with 
(PI. X. P"ig. 3) which is a diagramatic view of the median longitudinal section 
through the rabbit's stomach and the Oesophagus shows, the difference is 
strikirg between the gastric pouches of the animals referred to; if the stomachs 
of these iwo animals are taken as being equal in bulk, the digestive surface 
of the rat's stomach is in extent only half of that of the rabbit. 
As the necessary consequence of such a gastric construction as above 
given, the distribution of the gastric glands of the rabbit shows correspond- 
