The greatest difficulty in the mind of the medical man, with regard to the possibility of maternal impression being communicated in any way to the foetus, is, as we have said, his knowledge of the anatomy of mother and foetus. While it is {67} generally supposed that the mother is very intimately connected with her child _in utero,_ the actual connection is by no means so direct as might be expected from the popular impression. It is usually considered that the mother's blood flows in the child's veins; but this is absolutely false. The child's blood is formed independently of the mother's blood quite as is that of the chick in the egg. At all times the blood of the child remains quite different in constitution to that of its mother. It contains many more red cells than does her blood and differs in other very easily recognisable ways. Mother and child are connected by means of an organ known as the placenta, which is attached very closely to the uterine wall and from which through the cord the blood of the foetus circulates. This placenta constitutes the so-called afterbirth. The mother's blood flows in one portion of it, that of the child in another, and they always remain distinct and separate from each other. The gases necessary for the child's life diffuse through the membrane which separates the two different bloods, and the salts and soluble proteids necessary for the child's nutrition, as well as the water necessary for its vital processes, all pass through this membrane, but at no time is there any direct blood connection between mother and child. Indeed, for a large part of the formative period of the foetus life, that is, during the first two months of its existence, the ovum is not very closely attached to the uterus at all, but grows by means of the vital power which it has within itself. Nor is there any direct nervous connection between mother and child; indeed, there are no nerves at all in the placenta, and none in the cord through which all communications between mother and child must pass. It seems impossible to explain, then, how maternal impressions can so effectively pass from mother to child; and indeed, the whole subject, when looked at in this way, is apt to be considered legendary, and the facts adduced in support of the theory of maternal impressions are practically sure to be thought mere coincidences. A little knowledge here might seem to justify many things that more complete knowledge fails to be able to find any reasons for. {68}