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PROFESSOR ARTHUR ROBINSON ON 
Plate VI. 
Fig. 31. Section through the ruptured ovarian follicle of a ferret-polecat hybrid 53J hours after 
insemination. The orifice is contracted and firmly plugged, blood-vessels are fairly numerous around the 
periphery of the follicular epithelium, and the redistension of the cavity of the follicle with tertiary follicular 
fluid has taken place to a slight extent. x 30. (Specimen P.D. A. 31/15. L.F1. 53 J hours.) The ova 
are in the middle of the oviduct in the 2-cell stage. I.H. 
Fig. 32. Section through the ruptured ovarian follicle of a ferret 64 hours after insemination. The 
orifice of the follicle is more contracted than in the specimen represented in fig. 33, and the redistension of the 
follicle is more advanced. Blood-vessels are numerous in the follicular epithelium. x 30. The ova are in 
the middle third of the oviduct, some in the 4-cell and some in the 8-cell stage. (Specimen G-.A. 4/15. 
L.Z. 64 hours.) I.H. 
Fig. 33. Section through the ruptured ovarian follicle of a ferret 64 hours after insemination. The 
orifice of the follicle is a little more contracted than in the follicle shown in fig. 34. Blood-vessels are 
numerous in the follicular epithelium and around its periphery, and the redistension of the follicle has taken 
place to a slight extent, x 30. The ova are in the middle third of the oviduct, some in the 4- and some in 
8-cell stage. (Specimen G.A. 4/15. L.Z. 64 hours.) I.H. 
Fig. 33a. Section through a portion of the wall of the follicle represented in fig. 33. x 540. Showing 
the relation of the blood-vessels to the follicular epithelium. 
Fig. 34. Section through the ruptured ovarian follicle of a ferret polecat hybrid 53| hours after 
insemination. The orifice of the follicle is very much reduced, and the cavity of the follicle is considerably 
redistended. The ova are in the middle third of the oviduct in the 2-cell stage. (Specimen P.D.A. 31/15. 
Li FI. 531 hours.) I.H. 
Fig. 35. Section through the ruptured ovarian follicle of a ferret 70 hours after insemination. The orifice 
of the follicle is closed externally, and the redistension of the cavity is well advanced. (Specimen. The ova 
are in the middle third of the oviduct in the 8-cell stage. (Specimen F.D.A. 23/15. L.F1. 70 hours.) E. 
Fig. 36. Section through the ruptured ovarian follicle of a ferret 69f hours after insemination. The 
orifice of the follicle is completely closed, and the redistension of the cavity is well advanced. The ova are in 
the middle third of the oviduct, some in the 6- and some in the 8-cell stage. x 30. (Specimen F.D.A, 
21/15. R.Z. 69f hours.) I.H. 
. Fig. 37. Section through the ruptured ovarian follicle of a ferret 74 hours after insemination, The 
orifice is completely closed, and the redistension of the cavity is practically complete. x 30. The ova are in 
the middle third of the oviduct, some in the 6- and some in the 8-cell stage. (Specimen F.D.A. 44/15. R.F1. 
74 hours.) E. 
Fig. 38. Section through the ovary of a ferret 69f hours after insemination, showing a ruptured, 
closed, and redistended follicle and an unruptured follicle with a ripening ovum. x 30. The ova from 
the ruptured follicles of the ovary are in the middle third of the oviduct, some in the 6- and some in the 8-cell 
stage. (Specimen F.D.A. 21/15. R.Z. 69f hours.) I.H. 
Plate VII. 
Fig. 39. Section through part of the ovary of a ferret in the thirty-third day of oestrus, showing 
part of the wall of & large normal follicle and several degenerate follicles. x 40. The animal was not 
inseminated, and insemination was not attempted. (Specimen F.G.A. 18/15. R.F. 32 days’ oestrus.) E. 
Fig. 40. Section through a portion of the ovum and the ovarian cumulus in the ovarian follicle of 
a ferret-polecat hybrid in the pro-oestrum. The nucleus of the ovum is placed peripherally, close against the 
oolemma ; mitosis is taking place in two of the cells, which would have formed cells of the corona radiata, and 
the more peripheral cells of the cumulus are beginning to be separated from the more centrally placed cells by 
fluid-filled spaces. x 470. (Specimen P.G.B. 1/15. L.Mx. Early pro-oestrum, not inseminated.) I.H. 
Fig. 41. Section through a part of the ovum, the nucleus, and part of the corona radiata of the follicle 
ovum of a ferret 19f hours after insemination. x 1000. The nuclear membrane is still quite distinct, 
and chromosomes have not yet formed. The nuclei of most of the corona radiata cells have begun to migrate 
