OVARIAN FOLLICLES IN FERRETS AND FERRET-POLECAT HYBRIDS. 361 
peripherally. Mitochondria are visible in the bodies of the cells of the corona radiata. (Specimen F. 
1-2/08. 19f hours.) H.E. 
Fig. 42. Section through the cumulus of an unruptured ovarian follicle of a ferret 27£ hours after 
insemination, x 240. Showing the peripheral migration of the nuclei of the cells of the corona radiata 
and the commencing dispersion of the more peripherally situated cumulus cells. The membrana interna 
is seen on the periphery of the cumulus. (Specimen F.G.A. 1/15. R.Z. 27J hours.) I.H. 
Fig. 43. Section through part of the follicular ovum arid tli'e corona radiata of a ferret 41J hours 
after insemination. x 1000. The peripheral extension of the cells of the corona radiata and the 
peripheral migration of their nuclei is practically completed. Mitochondria are visible in the cell bodies 
of the corona radiata cells. The nuclear membrane has almost entirely disappeared, and chromosomes 
have definitely formed. (Specimen F.G.A. 2/15. L.Z. 41^ hours.) I.H. 
Fig. 44. Section through the follicle ovum and the corona radiata of a ferret 301,- hours after insemination, 
x 310. The ovum is in the latter part of the anaphase of mitosis, and the typical arrangement of the 
cells of the corona radiata and their nuclei is well shown. (Specimen F.D. D/16. L.P.N.F. 301- 
hours.) I.H. OG. 
Plate VIII. 
Fig. 45. A portion of the ovum represented in fig. 47. x 1000. Showing the structure of the 
corona radiata cells and some of the features of the protoplasm of the ovum. 
Fig. 46. Section through the cranial end of the uterine cornu and a terminal fimbria of the oviduct 
of a ferret-polecat hybrid 31^ hours after insemination, -showing an ovum surrounded by its corona and 
a portion of the contents of the ovarian follicle escaping into the peritoneal cavity, x 19. (Specimen 
P.D. C/16. L.Per. 31£ hours.) I.H. O.G. 
Fig. 47. The ovum shown in fig. 49. x 310. Showing the second maturation spindle in the upper 
and left part of the body of the ovum and the arrangement of the cells, and. nuclei of the corona radiata. 
Fig. 48. Section of a portion of the wall of the ovarian follicle of a ferret-polecat hybrid at the 
commencement of the early pro-oestrum. x 300. The portion of the wall shown in the figure is in the 
region of the ovarian cumulus. It demonstrates the arrangement of the follicle cells and their commencing 
dissemination, and shows the relationship of the blood-vessels to the external limiting membrane of the 
follicle. (Specimen P.G.B. 1/15. L.Mx.) I.H. 
Fig. 49. Section of a portion of the wall of a ripe unruptured ovarian follicle of a ferret-polecat hybrid 
31| hours after insemination. x 310. The part of the wall seen in the figure is on the opposite side 
to the ovarian cumulus. The relation of the follicular cells to the blood-vessels and to the interstitial 
cells of the sheath of the follicle is seen. (Specimen P.D. C/16. L.Per. 31^ hours.) I.H. O.G. 
Fig. 50. Section through a portion of the wall of the unruptured follicle of a ferret 41| hours after 
insemination. x 300. The ovum in the follicle was ripening. The section shows a stage of the invasion 
of the follicular epithelium by the blood-vessels. (Specimen F.G.A. 2/15. L.Z. 41 J hours.) 1,H. 
Fig. 51. Section through a portion of the wall of a full-grown normal ovarian follicle of a ferret, 
x 800. Showing the positions of the fat granules in the follicular cells and in some of the interstitial cells. 
(Specimen F.G.A. 18/15. R.F1. 32 days’ oestrus.) 
Plate IX. 
Fig. 52. Section through a portion of the wall of a fully-grown ovarian follicle of a ferret. The animal 
was in full heat, and was killed six days after insemination had been unsuccessfully attempted. x 310. 
The section shows an early stage in the formation of the internal limiting membrane, its connection with the 
follicle cells and with the reticulum of the primary liquor folliculi. It also shows the external limiting 
membrane and the relation of the latter to the blood-vessels. (Specimens F.Z.R. 1/14. Insemination 
unsuccessfully attempted.) I.H. 
Fig. 53. Section through the ovarian cumulus of a fully-grown ovarian follicle of a ferret in full heat 
and not inseminated. x 310. Showing the commencing formation of the internal limiting membrane on 
the surface of the cumulus. (Specimen F.D.A. 40/15. L.Z. 23 days post-partum in full heat.) I.H. 
Fig. 54. Section through a portion of the wall of a fully-grown ovarian follicle. x 1000. Showing 
