xiv ILLUSTRATIONS 



PAGE 



24 to 27. Developing ova from ovary 120-121 



28 Ovary at birth, showing primordial follicles . . • .123 



126 



29. Young oocyte . . ■ 



30. Young human Graafian follicle 127 



31. Human ovum at termination of growth period . . .128 



32. Human ovum examined fresh in the Uquor foUicuU . . 129 



33. Becently ruptured follicle of mouse 144 



34. Early stage in formation of corpus luteum of mouse . . 145 



35. Late stage in formation of corpus luteum of mouse . . .146 



36. Corpus luteimi of mouse fully formed 147 



37. Section through old corpus luteum 153 



38. Section through foUicle in early stage of degeneration . . 155 



39. Section through follicle in late stage 157 



40. Section through human testis and epididymis 166 



41. Section through testis of monkey . .... 167 



42. Section through portion of two seminiferous tubules in testis 



of rat 169 



43. A cell of Sertoli with which the spermatids are beginning to be 



connected (human) 170 



44. Diagram illustrating the cycle of phases in spermatogenesis . ib. 



45. Scheme of spermatogenesis and oogenesis 171 



46. Human spermatozoa on the flat and in profile .... 173 



47. Human Spermatozoa . . . . . ■ • .174 



48. Different forms of spermatozoa from different species of 



animals .......... 175 



49. Diagram illustrating wave-like movement of swimming sperma- 



tozoon .......... 177 



50. Successive stages in the fertiUsation of an ovum of Echinus 



esculentus, showing the entrance of the spermatozoon 188 



51. Three stages in the conjugation of male and female nucleus 



{Echinus) 189 



52. Fertilisation process in bat's ovum . . . . . .190 



53. Passage of convoluted seminiferous tubules into straight 



tubules, &c. . ... ... 228 



54. Transverse section through the tube of the epididymis . . 229 



55. Transverse section through commencement of vas deferens . 230 



56. Section through part of human prostate .... 235 



57. Section through prostate gland of monkey . . . 237 



58. Transverse section through adult human penis . 243 



59. Section through erectile tissue . ... 244 



60. Part of transverse section through penis of monkey . . . 245 



61. Distal end of ram's penis, showing glans and filiform appendage 247 



62. Transverse section through filiform appendage of ram . . 248 



