Katharine Foot and E. C. Strobell 239 



Photo. 36. x 710. Section of a ring nucleolus of an oocyte from the 

 ovary. Fixative, Lindsay Johnson's fluid. Stain, acid fuchsin. 



Photo. 37. x 710. Section of a vacuolated nucleolus. A small accessory 

 nucleolus is also present. Fixative and stain same as Photo. 36. 



Photo. 38. x 710. Section of a ring shaped nucleolus of an oocyte from 

 the ovary. Fixative, Merkel's fluid followed by osmic acid. Stain, iron 

 haematoxylin. 



Photo. 39. x 710. Section of a vacuolated nucleolus from an ovarian 

 oocyte and near it an accessory nucleolus. Fixative, picro-sulphuric followed 

 by osmic acid. Unstained. 



Photo. 40. x 710. Section of a vacuolated nucleolus from an ovarian 

 oocyte and near it a small accessory nucleolus. Fixative, picro-sulphuric 

 followed by osmic acid. Unstained. 



Photo. 41. x 710. Section of a vacuolated nucleolus from an ovarian 

 oocyte. This nucleolus appears to be surrounded by a definite membrane and 

 this is shown in three consecutive sections. Fixative, picro-sulphuric. Stain, 

 iron haematoxylin. 



Photo. 42. x 710. Section of a vacuolated nucleolus from medium sized 

 ovarian oocyte. Fixative, corrosive sublimate. Stain, iron hsematoxylin. 



Photo. 43. x 710. Section of a ring shaped nucleolus in oocyte from a 

 receptaculum ovorum. Fixative, corrosive acetic (10 per cent acetic). Stain, 

 iron haematoxylin followed by dilute Bismarck brown. 



Photo. 44. x 710. Section of a ring shaped nucleolus in an ovarian oocyte. 

 Fixative, Graf's picro-formalin followed by osmic acid. Stain, iron haema- 

 toxylin. 



Photo. 45. x 710. Section of a crescent shaped nucleolus in ovarian oocyte. 

 Fixative, Graf's picro-formalin followed by osmic acid. Unstained. 



PLATE in. 



All sections 2i/^ /z. 



Photos. 46 to 49. X 1000. Four sections selected from eighteen of a 

 germinal vesicle of an oocyte first order from a receptaculum ovorum. 

 Photos. 46 to 48 are consecutive sections, and Photo. 49 is the third section 

 beyond Photo. 48 and is one of three consecutive sections in which the large 

 vacuolated nuoJeolus is present. There are two accessory nucleoli also present 

 in this section. All these sections show the chromatin segregated into more 

 or less definite filaments and Photo. 47 shows a filament with what appears to 

 be a longitudinal split. Fixative, saturate corrosive sublimate. Stain, iron 

 hsematoxylin. 



Photo. 50. x 1000. Peripheral section of a germinal vesicle of an oocyte 

 first order from a receptaculum ovorum showing a ring shaped nucleolus. 

 Fixative, platino-osmic. Stain, iron haematoxylin followed by dilute Bismarck 

 brown. 



Photos. 51 and 52. x 1000. Two consecutive sections of a germinal 

 vesicle of an oocyte first order from a receptaculum ovorum. Each section 

 shows a ring chromosome, the two differing greatly in size. The prnicipal 

 nucleolus is present in this germinal vesicle and intact. Fixative, saturate 

 corrosive sublimate. Stain, Bismarck brown. 



