xiv ILLUSTRATIONS 



FIG. '"'"^ 



24 to 27. Developing ova from ovary 120-121 



28. Ovary at birth, showing primordial follicles . . . ■ 



29. Yoimg oocyte ^^® 



• 1 1 97 



30. Young human Graafian foUicle . . . ■ - . I'^i 



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



32. Human ovum examined fresh in the liquor folUouli . . • 1^9 



33. Recently ruptured follicle of mouse 1'** 



34. Early stage in formation of corpus luteum of mouse • 1*5 



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



36. Corpus luteum of mouse fully formed 1'*' 



37. Section through old corpus luteum ...... 153 



38. Section through follicle 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. Difierent forms of spermatozoa from different species of 



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



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



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



50. Successive stages in the fertilisation of an ovum of Ec/^inus 



esculentus, showing the entrance of the spermatozoori . 188 



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



(Mchinua) ^ . 189 



52. Fertilisation process in bat's ovum . . . . . ^ 1 90 



53. Passage of convoluted seminiferous tubules into straight \ 



tubules, &c ... fe28 



54. Transverse section through the tube of the epididymis . . 2^9 



55. Transverse section through commencement of vas deferens . 23 



56. Section through part of human prostate .... 2\ 

 57.. Section through prostate gland of monkey . . . 23\ 



58. Transverse section through adult human penis 24^ 



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 



