x CONTENTS. 



PAGE 



Hypothetical Development of the Blastodermic Vesicle in Primates 116 



Relationsof the Embryo to the Uterus, Il & 



Ovum of a Monkey in the Second Stage, - I21 



Human Embryo in the Second Stage I2 3 



Embryo of a Gibbon in the Third Stage I2 7 



Human Embryo in the Fourth Stage with Medullary Plate, 129 



Human Embryo in the Fifth Stage with Open Medullary Groove, I3 1 



Human Embryo in the Sixth Stage with Medullary Canal I3 2 



Human Embryo in the Seventh Stage with One Gill-cleft, 135 



Human Embryo in the Eighth Stage with Two Gill-clefts *35 



Human Embryo in the Ninth Stage with Three Gill-clefts, 138 



Human Embryo in the Tenth Stage with Four Gill-clefts, I4 1 



Human Embryo in the Eleventh Stage with Limb-buds H 2 



Human Embryo of Twenty-six Days, H3 



Human'Embryo of Twenty-eight Days, 143 



Embryos of the Second, Third, and Fourth Months 145 



CHAPTER IV. STUDY OF PIG EMBRYOS, 157-268 



Methods of Obtaining Embryos, *57 



The Making of Serial Sections, 158 



Selection of the Planes of Section and the Stages for Practical Study, 158 



The Study of the External Form, 159 



Pig Embryo of 10 mm , 160 



Pig Embryo of 12 mm. General Anatomy, 162 



Pig Embryo of 15 mm. (External Form), , 17 



Pig Embryo of 20 mm. (External Form), I7 1 



Pig Embryo of 12 mm. (Studied in Sections), . . 173 



The Study of Transverse Sections, 1 75 



Section through the Upper Part of the Otocyst, . . .' 175 



Section through the Lower Part of the Otocyst, 181 



Section through the First Gill-cleft, 184 



Section through the Second Gill-cleft, 187 



Section through the Third Gill-cleft 190 



Section through the Fourth Gill -cleft, 193 



Section through the Anterior Limbs and Heart, 195 



Section to show the Brachial Plexus, 199 



Section through the Stomach and Liver, 201 



The Study of Sagittal Sections, 205 



Median Section of the Head, 205 



Section of the Head through the Principal Ganglia, 208 



The Study of Frontal Sections, 211 



Section through the Trigeminal Roots, 212 



Section through the Acustico-facial Ganglion, . 213 



Section through the Otocyst 214 



Section through the Dorsal Vertebrae, 215 



Pig Embryo of 9 mm. (Studied in Sections), 217 



Transverse Section through the Branchial Arches, 217 



Sagittal Section to the Right of the Median Plane, 219 



Frontal Section through the Mid-brain and Fore-brain, . . 222 



Frontal Section through the Umbilical Opening, 223 



Frontal Section through the Second and Third Gill-clefts, 227 



Pig Embryo of 6 mm. (Studied in Sections), 228 



Pig Embryo of 17 mm. (Studied in Sections), 231 



Transverse Section through the Lungs, 231 



Section through the Wolffian Body and Genital Gland, 235 



Section through the Kidney, 237 



Frontal Section of the Umbilical Cord, 239 



Pig Embryo of 20 mm. (Studied in Sections), 240 



Transverse Section through the Snout, 240 



Transverse Section through the Lower Part of the Neck, 241 



Transverse Section through the Lungs, 244 



Transverse Section through the Posterior Limbs, 247 



Transverse Section through the Mammary Anlage, 249 



