ORIGIN OF GASTRIC GLANDS OF ACANTHIAS 363 
DISCUSSION OF RESULTS AND LITERATURE 
Miss Ross (’02), in her investigations on the development 
of the gastric glands in Desmognathus, Amblystoma, and 
pig, finds that the round granular cells which give origin to the 
glands appear as distinct cells with the differentiation of the 
entoderm. These gland cells occur at the base of the epi- 
thelium in close contact with the basement membrane. 
In addition to Miss Ross (’02), Toldt (’81) also maintains that 
the beginnings of the gastric glands in the cat are represented 
by granular cells, which are interpolated at the basal parts 
of the epithelial cells. There are, however, numerous other 
investigators who ascribe the origin of glands to epithelial pro- 
jections, or outgrowths,‘ among whom may be mentioned K@6l- 
liker (52), Brand (78), Griffini and Vassale (’88), Oppel (’96), 
Minot (’02), and Peterson (09). Johnson (’10) finds in a human 
embryo of 120 mm. that the beginnings of the gastric glands 
appear as knob-like outgrowths at the bottoms of the gastric 
pits. It is generally admitted by those who believe that the 
glands arise from downgrowths of the surface epithelium, that 
the gastric pits—later elongated to form grooves—give origin 
to the glands in this manner. 
In specimens of Squalus acanthias there are no gastric pits; 
the longitudinal folds, which are presumably the forerunners 
of the villi in higher forms, are variable in their number, location, 
and size. In all probability, their presence is due to the con- 
traction of the muscular coats. Consequently, gland develop- 
ment must go on in a very different manner from those forms 
where all these features can be readily identified. Peterson 
(09) states that in a number of selachians he has found that 
they arise from epithelial outgrowths directly. With regard 
to the origin of the outgrowths themselves, and their further 
history as based more particularly on a study of Acanthias 
vulgaris, he states: 
4 Bensley (’00) finds in a Urodele larva 11 mm. in length that the oesopha- 
geal glands also appear as tubular downgrowths of the foregut entoderm. He 
believes that these glands represent gastric glands whose development has been 
arrested. 
