498 Edwin G. Kirk. 
mucous pyloric tubules is absolutely sharp. Many of the mucous 
cells in the gland tubules are mitotic, as are also the embryonic 
cells. The transition, then, between fundus and pylorus is 
absolute (point 4) and marked by the sudden difference in size of 
tubules, and by absence of parietals in the pylorus. Rarely, the 
surface fundie cells show a very slight line of mucous stain, very 
inconstant, and probably absorbed from the general stomach 
content. 
From now on, mitotic activity is incessant at all depths of all 
the gland tubules. Surface mitoses also occur, but are much rarer. 
In the pylorus of 7-8 cm., and fundus of 9-10 cm., secondary 
gland processes appear at the bottoms of the primary tubules. 
They are of the same general nature as the primary processes, 
being intra epithelial for a short time, but being very soon rein- 
forced by mesoblast. By this upgrowth they at first render the 
lower portion of the tubule compound, but as they progress until 
they reach the surface, the result is not a compound tubule, 
but two independent glands. This mode of increase of the glands 
is very common in fundus and pylorus, in these earlier stages. 
In the cardia, the same process occurs later (14—15em.). These 
upgrowths are of the same nature as the primary ones, being intra- 
epithelial for ashort time, but being speedily reinforced by meso- 
blast. 
The true compounding occurs somewhat later, with the fail- 
ure of these secondary processes to reach the surface. This begins 
in the pylorus about 17 cm.,in the fundus about 19-20 cm.,in the 
cardia about 21-22 em. During this compounding, there is enor- 
mous proliferative activity in the depths of the tubules, as evinced 
by the numerous mitoses, and by the rapid downward elongation 
of the glands. This applies especially to fundus and pylorus, 
but many mitoses are found even in the cardia. 
After the gland-compounding has been largely completed (25— 
29 cm.), the mitoses are somewhat less frequent, but are still 
present in all parts of the tubule, especially in the elongating fun- 
dus segments. 
1° In the compounding of the cardiac tubules we shall find a complicating factor, 
the evagination of parietal tubules. 
——— a lo 
