240 Fii-st Ahilunition S|)iii(llc of Allolohopliora Kd'tida 



Photos. 53 and 54. ■, iUUU. Each of these phoLograyhs shows one of three 

 consecutive sections of a vacuolated nucleolus in an oocyte first order from a 

 receptaculum ovorum. Fixative, saturate corrosive sul)limate. Stain, iron 

 htpmatoxylin. 



Photo. 55. X 710. Section of a nucleolus in an ovarian oocyte. Fixative, 

 bichromate-cupric sulphate. Stain, iron haematoxylin. 



Photo. 56. x 1000. Part of a section of a germinal vesicle of an oocyte 

 first order from a receptaculum ovorum showing the principal and the 

 accessory nucleoli. Fixative, platino-osmic. Stain, iron haematoxylin fol- 

 lowed by dilute Bismarck brown. 



Photo. 57. X 710. Section of a vacuolated nucleolus in an ovarian oocyte. 

 Fixative, bichromate-cupric sulphate. Stain, iron haematoxylin. 



PiioTO. 58. X 1000. Section of a germinal vesicle of an oocyte first order 

 from a receptaculum ovorum. This is one of four consecutive sections of the 

 principal nucleolus. Fixative, corrosive acetic (5 per cent acetic). Stain, 

 iron haematoxylin followed by Bismarck brown. 



Photos. 59 to 62. x 1000. Four sections selected from sixteen of a germ- 

 inal vesicle of an oocyte first order from a receptaculum ovorum. The first 

 three sections are consecutive. The prinvipal niicleohis of Photos. 59 and 60 

 shows no connection with the chromatic filaments. Fixative, Rabl's picro- 

 sublimate. Stain, iron haematoxylin followed by Bismarck brown. 



Photos. 63 to 65. x 1000. Three sections of a germinal vesicle of an 

 oocyte first order from a receptaculum ovorum. Photo. 63 shows an accessory 

 nucleolus with transverse sections of a chromosome at opposite sides of it. 

 The principal riucleolus is in the sixth section from the accessory nucleolus. 

 In Photo. 64 there is a chromosome in the form of a figure eight and in Photo. 

 65 a rod shaped chromosome and transverse sections of two more. Fixative, 

 saturate corrosive sublimate. Stain, iron haematoxylin. 



Photo. 66. x 1000. Section of a germinal vesicle of an oocyte first order 

 from a receptaculum ovorum showing chromatic filaments and an accessory 

 nucleohis attached to a chromatic filament. Fixative, saturate corrosive subli- 

 mate. Stain, iron haematoxylin. 



Photo. 67. x 710. Section of a nucleolus of an oocyte from the ovary. 

 Fixative, bichromate-cupric sulphate. Stain, iron haematoxylin. 



PLATE IV. 



The section of Photo. 76 is 3 // , of Photo. 11 2 /i. and all others on this plate 

 are 2^2 }i. 



Photos. 68 to 73. x 1000. Six consecutive sections of an oocyte first 

 order, from the receptaculum ovorum. Photos. 68 to 69 are entire sections 

 unstained. They demonstrate very clearly the presence of the polar-ring 

 substance (yolk-nucleus, archoplasm) and the deuto-plasmic granules black- 

 ened by the osmic in the fixative (platino-osmic). In Photos. 70 to 73 only 

 the germinal vesicle and a small part of the surrounding cytoplasm are 

 reproduced. Photo. 70 shows a group of chromosomes. Photo. 71 the principal 

 nucleolus and a small accessory nucleolus. Photo. 72 a large acvcisory nucleo- 

 lus and a cross shaped chromosome, and Photo. 73 a second section of th3 

 accessory nucleolus of Photo. 72. Photos. 70 to 73 are stained with iron 

 haematoxyliri followed by dilute Bismarck brown. 



