Folds, ileo-caecal, 260 Follicles, solitary, 196 Foramen of Winslow, 174 boundaries in adult human subject, 184 caudal boundary, 178 in lower mammals, 183 relation to duodenal adhesion, 184 in _Tamandua bivittata_, 183 Foregut, comparative anatomy of, 42 divisions of, 191 extent and contained segments, 38 Formative yolk, 19 Fossa duodeno-jejunalis, 96 ileo-caecal, 260 intersigmoidea, 97 of Treitz, 92, 96 Function of caecum, 219 of pyloric appendices, 221 of pyloric caeca, 221 of spiral fold of intestinal mucous membrane, 220 Furrow, primitive intestinal, 22 _Gadus callarias_, ileo-colic junction of, 201 pyloric appendices in, 120 _Galeopithecus_, biliary ducts in, 145 ileo-colic junction and caecum of, 213 Gall-bladder, development of, 142 occurrence of, 144 Gastric diverticula of Carnivora, 48 of Herbivora, 48 of Omnivora, 48 Gastro-hepatic omentum, as part of ventral mesogastrium, 165 Gastro-splenic omentum, 109 Genito-urinary sinus, 27 tract, male, in _Platypus anatinus_, 26 Germinal area, 20 membrane, 20 spot, 19 vesicle, 19 Glands of Lieberkuehn, 194 Glandular stomach of birds, 50 _Gobius_, stomach of, 45 _Gorilla savagei_, ileo-colic junction and caecum of, 216 Graafian follicle, 19 Greater curvature, first appearance of, 41 Groove, medullary, 21 primitive intestinal, 22 _Halicore_, ileo-colic junction of, 208 _Halmaturus derbyanus_, ileo-caecal folds of, 263 ileo-colic junction and caecum of, 205 stomach of, 47 _Hapale jacchus_, ileo-colic junction and caecum of, 214 _vulgaris_, duodenal fold, 93 _Heloderma suspectum_, ileo-colic junction of, 211 Hepatic antrum of lesser sac, 170 artery, 65 development of, 179 in relation to foramen of Winslow, 180 relation to duodenal adhesion, 182 relation to primitive dorsal mesentery, 182 cylinders, 143 ducts, 145 flexure, formation of, 76 recess of lesser sac, 177 ridge, 142 veins, 148 venous circulation, comparative anatomy of, 154 direction of current, 152 summary of development, 153 Hepatic-portal system in Selachian, 155 in Urodele Amphibian, 157 vein in _Iguana_, 160 Hepato-cystic duct, 145 Hepato-enteric duct, 145 Herbivora, gastric diverticula of, 48 stomach of, 46, 47 Herbivorous birds, stomach of, 50 Herons, caecum of, 204 stomach of, 50 _Hippopotamus_, ileo-colic junction of, 209 Human caeca compared with those of the Anthropoidea, 247 _Herpestes griseus_, ileo-colic junction and caecum of, 212 _ichneumon_, ileo-colic junction and caecum of, 212 _Hyaena striata_, ileo-colic junction and caecum of, 212 _Hylobates hoolock_, ileo-colic junction and caecum of, 216 Hypoblast, 21 Hyracoidea, ileo-colic junction of, 210