If any quality, characteristic or trait of the father passes from him to his child, it is transmitted by, and through the spermatozoön, for that is the only thing that passes from the one to the other. So, if any quality, characteristic or trait of the mother passes from her to her child, it is transmitted by and through the ovum, that being the only thing that passes from her to it. Whatever power or influence the father’s body, or any organ or part of it, may have to affect or modify the body of his child or any part of it, must be effected by and through the spermatozoön before it leaves his genital organs; for it is clear that neither the father’s body, nor any organ nor part of it, has any power to affect, modify or differentiate the spermatozoön, nor any part of it, after it leaves his body. It is absurd to suppose that the father’s body, or any organ or part of it, can affect, modify or differentiate the spermatozoön, or any part of it, in such a manner that it shall cause the child to have qualities, characteristics and traits resembling those of the father. In fact he could not possibly know whether there is one, many, or none in his genital organs, at any given time, for a stronger reason no single organ nor any part of his body could possibly affect, modify nor differentiate the spermatozoön in such a manner as to cause the child, which arises from it to have organs and parts resembling those of the father. Thus, suppose the father has blue eyes. How could the father, or his eyes, possibly affect the spermatozoön in such a way as to cause the child’s eyes to be blue? How could the father, or his nose, modify the spermatozoön in such a manner as to cause the child’s nose to resemble the father’s nose. It would be absurd to suppose that the father’s brain and his vocal organs can affect the spermatozoön in such a manner as to cause the child to be a notable singer. Professor Weismann says: “It is well known that many mental and physical qualities of parents are transmitted to their children, such as the color of the eyes and hair, the shape and size of the finger nails; and not only these, but as everyone knows, even such minute and indefinable physical and mental characteristics as likeness of features, bearing, gait, handwriting, a mild and equable or passionate and irritable temperament.”--(Weismann on Heredity, 2, p. 14.)