the child to grow to resemble the cow on whose milk it is fed after birth, as to expect it to grow to resemble its mother, because of prenatal influence, as the term is customarily used, for once development has begun, the child draws nothing more than nourishment from its mother.
Of course we are accustomed to the pious rejoinder that man must not expect to understand all the mysteries of life; and to hear vague talk about the wonder of wireless telegraphy. But wireless telegraphy is something very definite and tangible—there is little mystery about it. Waves of a given frequency are sent off, and caught by an instrument attuned to the same frequency. How any rational person can support a belief in maternal impressions by such an analogy, if he knows anything about anatomy and physiology, passes comprehension.
Now we are far from declaring that a reason can be found for everything that happens. Science does not refuse belief in an observed fact merely because it is unexplainable. But let us examine this case of maternal impressions a little further. What can be learned of the time element?
Immediately arises the significant fact that most of the marks, deformities and other effects which are credited to prenatal influence must on this hypothesis take place at a comparatively late period in the antenatal life of the child. The mother is frightened by a dog; the child is born with a dog-face. If it be asked when her fright occurred, it is usually found that it was not earlier than the third month, more likely somewhere near the sixth.
But it ought to be well known that the development of all the main parts of the body has been completed at the end of the second month. At that time, the mother rarely does more than suspect the coming of the child, and events which she believes to "mark" the child, usually occur