Contributions to the history of development in animals. I. On foetal circulation / by William Macdonald.

  • Macdonald, William, 1797-1875.
Date:
1868
Catalogue details

Licence: Public Domain Mark

Credit: Contributions to the history of development in animals. I. On foetal circulation / by William Macdonald. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    the viscera and lower extremities as their necessities required. This appears to me a more rational way of accounting for the disparity of the head of the foetus and its lower extremities. If these reasons are admitted, and the grounds I have described for the views propounded in the former part of the communication are correct, I may be allowed to maintain— 1. That the hypothesis of the course of the foetal circulation, described during the last three centuries, and still obstinately maintained by the most distinguished anatomists, physiologists, and obstetricians, is inconsistent with correct anatomy, sound physiology, and the general laws of hydraulics. 2. That the theory now proposed, supported by the researches of anatomists, physiologists, and embryologists, is more rational and consistent with anatomy and physiology. 3. That it affords the true key to the whole foetal circulation, by the entire separation of the arteries from the cavities of the heart, whether consisting of one or four divisions, which are entirely and solely filled with venous blood. 4. This theory cannot be viewed as at all to be compared with the great Harveian discovery, but in the correction of a long prevalent error, it has the merit of at least capping and culminating it, on the principles of the immortal Harvey, who had overlooked it as completing his own. I feel convinced that till it is adopted there is little chance of any correct view of the foetal circulation being entertained. Having been challenged by more than one eminent physio- logist to adduce evidence experimentally in disproof of this old theory, which never was established on practical experi- ment or demonstration, nor during the three centuries of its predominance, I hold that it is with the supporters of that theory that the onus probandi and experimentaliter demon- strandi first lies, and I throw down the gauntlet to any one of the eminent anatomists, physiologists, or embryologists in the numerous medical schools of the vast metropolis or elsewhere, to adduce a single fact resting either on direct observation or experiment, showing the course of the blood from the placenta by the umbilical vein to the heart of the foetus ; or that the venous blood returns by the aorta and umbilical arteries in the cord to the placenta for oxidation. Till this is done, I feel no D