xvi ILLUSTRATIONS 



PIG. PASB 



147. Median longitudinal section of an early human ovum, 0'4 mm. in length 491 



148. Diagram of the earliest human ovum hitherto described - 494 



149. Section through the wall of the uterus in the early part of pregnancy 495 



150. Section of a portion of the wall of the human blastocyst 496 



151. Section of a portion of the necrotic zone of the decidua, etc. 497 



152. Section through embryonic region of ovum - - 498 



153. Condition of the glands at the beginning of pregnancy in man - 499 



154. Median longitudinal section of ejnbryo of 2 mm. 500 



155. Diagram of stage in development of human placenta - 501 



156. Fat in a villus of human placenta 504 

 'l57. Iron granules in a villus of the placenta in man 506 



158. The first stage in the revolution of the equine foetus 568 



159. The foal in the normal position for delivery - 569 



160. Virginal external os (human) . 583 



161. Parous external os (human) 583 



162. Section of mammary gland of woman 589 



163. Section of mammary gland (human) during lactation 590 



164. Section of mammary gland (human) in full activity 591 



165. Section through an alveolus with fat drops in cells 592 



166. Section of developing mammary gland of horse 606 



167. Section of mammary gland (human), showing developing alveoli - 607 



168. Photograph of mammary tissue of virgin rabbit 617 



169. Photograph of mammary tissue of pseudo-pregnant rabbit 617 



170. Masoulinisation of guinea-pig 696 



171. Feminisation of guinea-pig 697 



172. Feminised guinea-pig with large protruding teats and small penis 698 



173. Normal male guinea-pig with rudimentary teats and large penis 698 

 174-180. Diagrams from Minot's Problem of Age, Growth, and Death 704-710 



181. Growth of sheep 7,11 



182. Growth of boys and girls - 711 



183. Section through ovary of woman of fifty-six, showing degeneration of 



follicles, etc. - 716 



184. Section through uterine mucous membrane of woman of sixty 717 



185. Section through vaginal mucous membrane of woman of sixty-one 718 



186. Group of nerve-cells from the first cervical ganglion of a child at birth 719 



187. Group of nerve-cells from the first cervical ganglion of a man of 



ninety-two - - 720 



188. Land tortoise aged at least eighty-six, belonging to M. Elie Metohnikofi^ 722 



189. Lonk sheep aged eighteen years, with her last lamb - 723 



