89. Such is the real structure of the human placenta (77 to 88, inclusive). Its description is founded on positive and direct experiments, first-rate authorities, and anatomical inquiries, which may be repeated, referred to, or ascertained any day, and to which many can bear witness: any other description differing from it and not so grounded, must be erroneous. This view of the real structure of the placenta differs from that of Dr. Hunter only in the non-adoption of that great man’s notion that continuous vessels go from the uterus, _through_ the decidua, direct into appropriate cells or laminæ, where he supposed that the arteries deposited their blood, which the veins pumped back into the uterine system of the mother, after it had served the purpose of bathing the terminal or cotyledonic vessels of the fœtus. The existence of cells, however, has been frequently denied, and by none more stoutly than by Professor Lauth, of Strasburgh, and others; but as these individuals deny, at the same time, that which a hundred anatomists of great skill and veracity have seen, namely, the transmission of fluids, by means of decidual vessels, from the uterine system into the placenta, their opinion is liable to suspicion. However, it is unquestionably true, that on looking at the appearance exhibited by the fluid injected from the uterine vessels, in those portions of the placenta which it reaches, (Experiment at the Middlesex Hospital, 85,) we feel more inclined to consider it as dendritic and ramose, than extravasated or diffused. I entertain the former opinion. I submitted a thin section of the injected placenta (March, 1833) (85) to a powerful magnifying lens before a very strong flame of an argand burner, and could not perceive any sensible difference between the appearance of the red and that of the yellow injection. Now, that the latter, which was thrown in through the umbilical vessels, had been deposited within minute vessels, and not within cells, no one doubts. It is, therefore, likely that the other fluid is also so deposited. If Hunter and his followers were wrong in their conclusions, (though accurate in their experiments,) Professor Lauth, and the author of a paper on the placenta, inserted in the Philosophical Transactions for 1832, (who, by a most singular coincidence repeats all that Lauth had said long before him respecting the non-existence of cells and of continuous vessels from the uterus in the placenta) are not less chargeable with even greater errors; inasmuch as they have denied anatomical facts which have been observed and ascertained by many. They have overlooked the function of the decidual vessels, and they have said not a word of that beautiful arrangement of the fœtal vessels of the placenta which Dr. Hunter compared to the “vascular portion of the chorion forming part of the placentulæ in a calf,”[20] and which I have succeeded in demonstrating in a human placenta prepared for that purpose, and still in my