Mucous Membrane in the Human Embryo. 539 
12-15 longitudinal folds of the stomach mucosa in an embryo of 
two months. Koelliker (’69) found in an embryo of four months, 
3-4 folds; in another embryo of four months, 11-12; at three 
months, 5-6. He therefore regarded their number as variable. 
Toldt (81), in a study of cat embryos, considered the folds of 
the stomach as unimportant, being formed by the contraction of 
the musculature. 
TABLE 2 
Sromacu EprtHenium (Funpvus) 
THICKNESS OF 
EMBRYO SURFACE GASTRIC PITS GLANDS FOLDS 
EPITHELIUM 
ree , 2 Diam- | 
een, | Eageell [tm mm. Depth! | "ope) in apartin | Lenath' eter (8t ayuouter Hele 
. 7 mm. | 
Te We hs 1046 
Hoe" 3r 51) 048 | 
16 2-3 054 028 O09. | 2f 5-6 | .042 
19 223 |=. :048-|- 5-031 009 t 2-3 | .067 
D218. 9-31 \o55. |. 1048 O12 t V=109\18 
42 1-3 | .055| .041 |.012-.017|.036-. 048 10-12 | .25 
55 1 057 | 
or 
012° .048 —.007-. 012, .024~. 036) | 10-12 | .11 
91 1 .048|  .072 |.012+.030!.048-.084 
120 1 .029 .084.019-.036|.054-.108| 048 | .036 | 36 
187 1 .036 | .089 |.019-.038.068-.170| .120 | .038 | 88 
240 1 088 | 106 |.919-.038|.102-.238 .136 | .040 | ee 88 
Birth 1 048 108.02 ~.048.102-.176| 255 .048 70 
' Average of a number of measurements. 
t Irregularly placed. 
SMALL INTESTINE 
Vacuoles and Diverticula. In the following section of the present 
paper the development of the intestinal villi and glands has been 
given especial attention. The vacuoles of the solid stage of the 
duodenum and intestinal diverticula are briefly described, par- 
ticularly, because of a probable relation which they bear to the 
vacuoles found in the cesophagus and the stomach, and because 
they are closely associated with the development of villi. 
