History of the development of the human ovum, with a comparative view of the development of the ova of mammalia and birds / translated and abridged from the German of Dr G. Valentin, of Breslau, by Martin Barry.

Date:
[1836?]
Catalogue details

Licence: Public Domain Mark

Credit: History of the development of the human ovum, with a comparative view of the development of the ova of mammalia and birds / translated and abridged from the German of Dr G. Valentin, of Breslau, by Martin Barry. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    size ; De Graaf, however, was not in a condition to recognize in them an embryo. He failed to do this also, as, later, Prcvost and Dumas, and Von Baer have likewise done, in ova of the eighth day, because the latter are then, on the one hand, already firmly fixed on the internal surface of the uterus, on the other hand, so extremely delicate, that, with the slightest injury, they are lacerated. In some ova of the ninth day the embryo presented itself to De Graaf as a faint cloudiness, whereas he distinctly saw it already forward in its development in ova of the tenth day. Had Regner de Graaf made use of the microscope in these examinations, science would, more than a century and half ago, have been enriched with results, which unfortunately in the pre- sent day, we discover to be still wanting. 2. Valentin then shows that the enquiries of those who suc- ceeded de Graaf were not characterized by equal circumspection, pains, and fundamental research, and that the authority of Val- lisneri, Kuhlemann, Haller, and others, suppressed the truth, that the ovulum itself was contained in the Graafian vesicle, and substituted for it the erroneous assertion that a fluid merely, without a covering, was poured out of the ovary into the tubes, or that, as Osiander even in the beginning of the nineteenth century maintained, the ovaries were not at all concerned in con- ception. Cruickshank, however, has the merit of having repeat- ed and confirmed the experiments of De Graaf, but he added nothing really new, and through some errors, even darkened the subject. 3. Provost and Dumas have more recently given a senes of laborious and minute experiments on the first effects of concep- tion in rabbits and dogs.* The following is from their observa- tions : Timeaf. Ovaries. Tubes. Horns of the uterus. ter coition. 4 hours. No change either in Lively motions of the dogs or in rabbits. animalcules of the se- men. 2 days. Ditto, except that the Do. Graafian vesicles had in- creased in size, aud the central point of their sur- face had become more transparent. 3 to 4 Graafian vesicles still days. larger, sometimes from 7-8 millimetres in dia- meter, in dogs. After 6 The Graafian vesicles to 7 days, opened, so that an aper- ture was seen in their sur- face. • Annalcs dcs Sciences Naiurclks, Vol. Hi. p. ] 13-133.