The volume of the transparent involucra is disproportionate to the embryo itself: yet the placental covering, with its filiform vessels, bears a still larger proportion to them; so that the want of equilibrium between the external and internal apparatus of the Ovum has destroyed, first the growth, and next the life of the embryo. The preparation is in the museum of St. George’s Hospital, and like the preceding preparation (5), has been flattened and pinned to a pasteboard—a mode which, for the _steady_ display of the peculiarities of the Ovum in both cases, was, perhaps, the most judicious. Fig. 7. Ovum denudatum, or diaphanous Ovum. (About eight weeks after menstruation.) Its structure is imperfect. It wants the nutritive membranes or involucra. It is defective also in the arrangement of the inner or secreting membranes. Hence the great accumulation of fluid within, and the scanty appearance of the filiform vessels without. The embryo has consequently been retarded in its development, which is scarcely greater than that of Ovulum No. 4, although the period at which the former had been ejected, was nearly twice as long as that of the latter. Fig. 8, and 9. Are also examples of denuded or diaphanous Ova, to which the same remarks apply as to the preceding specimen. The enlargement of Ovum 8 is even greater than that of Ovum 9: yet the embryo of the latter is more advanced and more clearly delineated by nature than is the case with Embryo 8. We know that these two Ova and No. 7, are more than two months old from the length of the umbilical cord as compared to that of the fœtus: for from the second to the sixth month of pregnancy, the length of the cord is proportionately greater than that of the fœtus.—(_See_ Meckel and others.) In examining these denuded or diaphanous Ova, I have been struck with that small circular spot on their surface, generally of an opaque colour, which has been called the _cicatricula_, and is not unlike that which is found in some of the Ova of birds. This spot is well marked by the artist in the last three specimens, and in two of the figures of _Plate 3_. I take the _cicatricula_ to be that part of the _Ovulum_ which adhered to its ovarian nest (called the _vesicula graafiana_), before it burst from the Ovarium to pass into the womb consequently on fecondation. It is to be seen on all the ovula so situated in the Ovaria of women, and is considered to contain the rudiments of the embryo, which certainly begin from a little straight line that may be distinctly seen in the _cicatricula_.—(_See_ Meckel, Adelon, Geoffroy St. Hilaire, Prevost, &c.) REMARKS.