From William Preyer   6 July 1877

Dear Sir,

You would extremely oblige me by sending me a copy of your paper “biography of a child” published in the “Mind”.¹ I have myself made some observations on the movements of new-born children and animals and particularly such mammals that are born with open eyes and teeth.²

I have cut out of the womb of guinea-pigs the young with their placentae and brought them up with bread and cow’s milk. These animals which never saw their mother behaved nearly in every respect like young guinea-pigs that are brought up by their mother. They begin to suck immediately, and, what seems very remarkable, one krept beneath the other ever so often and moved about pushing and knocking against the abdomen with the mouth exactly like young guinea-pigs behave towards their mother.

Once I convinced myself that a human child when only the head was out began to suck the finger I introduced into its mouth, particularly when I put it on the tongue. The eyes were then opened and even in this critical moment seemed to brighten and the face of the child 3 minutes after the head was out of the vagina seemed to betray that the introduction of the finger caused an agreeable sensation. But when I only touched the lips, the child did not suck. I have repeated this and several other experiments with new-born mammals and as they prove that undoubtedly many coordinated muscular actions are not acquired but inherited, I am occupied to find out which movements are only inherited and never acquired. As I am informed that your own observations are of the highest importance in this respect, you can easily imagine of how great an interest the original communication to the “Mind” (a periodical scarcely known here) must be for me.

Your’s most truly | W^m. Preyer