Concerning the immediate Matter, and Means of Life, and Nutrition, Authors are not agreed, nor is it the business of this place to reconcile, or decide their Differences, but to account for the Motion of the Blood through the Vessels only. In order to this, it will be necessary to observe, that the Pulsation of the Heart in a _Fœtus_ is so very weak and obscure, and the Motion of the Blood so extream slow and languid, as to be scarce, if at all perceivable, as has been experienced in the Dissection of Puppies before Respiration had. To produce such a feeble Palpitation, and creeping Motion, no greater force seems to be required, than may be deriv'd from the Communication between the Vessels of the Mother and _Fœtus_ in the _Placenta_. I am not ignorant, that divers very Learned Anatomists (whom the Crowd have implicitly follow'd) have absolutely rejected all Communication between these Vessels. But, with submission to Great Authorities, I think they have acted arbitrarily, and without sufficient Warrant from Reason or Experiment: For neither are the Arguments which they bring against it conclusive, nor the Office which they assign to the Umbilical Vessels in lieu of it, proper, or natural to those Vessels, or the reality of the Fact made out by any substantial Reasons. Those that reject this Communication usually do it in favour of one or both of these Opinions, that the Arteries of the _Uterus_ do deposite a Nutritive Juice, or a Juice impregnate _with Air_ in the _Placenta_, which is suck'd in by the _Umbilical_ Vein, and convey'd to the _Fœtus_, for the necessary Uses of Nutrition and Life. Now those that patronize either of these Opinions, lead Nature an unnecessary Dance. For if the _Maternal_ Blood does really contain any such _Nutritious_, or any such necessary _Aerial Particles_, why shou'd they be separated and extravasated, to be with difficulty receiv'd into the _Umbilical_ Vein, and again mixt with the Blood, when they might more easily have been imparted by the plain simple way of Transfusion from the Arteries of the _Mother_ to the Veins of the _Fœtus_. And, that this is the course which Nature takes in this Case, I am perswaded from the easiness and simplicity of the Method, which readily performs what might be perhaps in vain expected from the other, and wou'd over and above find them, what they seem to grope so blindly about for, a first Mover of the Blood in a _Fœtus_.