On the Histogenesis of Gastric Glands. 485 
3. In the pig, the mesodermic cores appear relatively much 
earlier—in fact so early that it was only after careful reconstruc- 
tions that the appearance of epithelial ridges slightly in advance 
was established. Toldt’s description for the pylorus is very 
similar. He admits that in this region there is no independent 
origin of the gland cells, with, later, secondary communications 
between these and the lumen. 
From 3 cm. on, the ridges of lamina propria grow rapidly up 
into the epithelial ridges (figs. 4 and 6), causing a correspondingly 
rapid heightening of the latter, and deepening of the glands. For 
the correct interpretation of certain papilloid structures seen in 
all stages of the gastric development up to about 23-27 em., it 
js essential to understand the exact way in which the irregularity 
of mesoblastic growth manifests itself. As has been indicated, 
the early, intra-epithelial ridges intersect in all directions. They 
are not straight, nor do they intersect often at right angles; rather 
they are short, very irregular, curved or angular, and they inter- 
sect at all angles. Now, when the mesoblastic ridges begin to 
reinforce them from below, the mesoblast pushes up much more 
rapidly at the nodal points of intersection of the ridges than along 
the intervening parts. The result is that in a sagittal section 
taken (fig. 7A) through the line a, b, c, d, the appearance seen 
in fig. 7B results. That is, we have in addition to the ridges the 
papilloid elevations a, c, and d, situated at the intersections of 
the ridges, and higher than the rest of the interglandular ridge. 
In cross or oblique section of the upper level of the mucosa, they 
are, of course very numerous, and appear like true papillae. One 
might readily gain the impressions, as did Brandt and others, that 
in the early stages there are no gland processes, but simply papillae, 
the depressed areas between them communicating with each 
other. Such a condition would be represented by fig. 7A, with 
all elevations except the nodal points effaced. But this is very 
different from the condition actually found—namely, that ridges, 
not so high, it is true, as the papillae, but still high in comparison 
with the depressed areas, run across from the base of each papilla 
to the adjacent one. This papilloid condition is marked from the 
