In the discovery of mammalian egg von Baer reported to have seen a yellow fleck inside the follicles; this could correspond to sighting- with the microscopes of that time- to the cumulus o-hutus, which convex face in the antrum could be described as a fleck or point?
Probably, the great Zoologist Karl Ernst von Baer investigated the problem of identifying the structure of the ovum of the dog and found it to be a small yellow spot floating in the follicular fluid. As a result of this work, he published in 1827 the first description of a mammalian egg, Epistola de ovi mammalium et hominis genesi (On the Origin of the Mammalian and Human Ovum).
The yellowish-white point that Karl Ernst von Baer could have seen might be the germinal vesicle possessing nucleolus in the diplotene-arrested oocyte inside the follicle of the dog ovary.
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