animals sexual intercourse necessitates a mounting or “climbing upon” the female has something to do with this association of ideas. Pulling off a branch to symbolize onanism is not only in agreement with vulgar descriptions of that act, but also has far-reaching parallels in mythology. But especially remarkable is the representation of onanism, or rather of castration as the punishment for onanism, by the falling out or extraction of teeth; for we find in folk-lore a counterpart to this which could only be known to very few dreamers. I think that there can be no doubt that circumcision, a practice common to so many peoples, is an equivalent and replacement of castration. And recently we have learnt that certain aboriginal tribes in Australia practise circumcision as a rite to mark the attaining of puberty (at the celebration of the boy’s coming of age), whilst other tribes living quite near have substituted for this practice that of knocking out a tooth. I will end my account with these examples. They are only examples; we know more about this subject and you can imagine how much richer and more interesting a collection of this sort might be made, not by dilettanti like ourselves, but by real experts in mythology, anthropology, philology and folk-lore. We are forced to certain conclusions, which cannot be exhaustive, but nevertheless will give us plenty to think about. In the first place, we are confronted with the fact that the dreamer has at his command a symbolic mode of expression of which he knows nothing, and does not even recognize, in his waking life. This is as amazing as if you made the discovery that your housemaid understood Sanscrit, though you know that she was born in a Bohemian village and had never learnt that language. It is not easy to bring this fact into line with our views on psychology. We can only say that the dreamer’s knowledge of symbolism is unconscious and belongs to his unconscious mental life, but even this assumption does not help us much. Up till now we have only had to assume the existence of unconscious tendencies which are temporarily or permanently unknown to us; but now the question is a bigger one and we have actually to believe in unconscious knowledge, thought-relations, and comparisons between different objects, in virtue of which one idea can constantly be substituted for another. These comparisons are not instituted afresh every time, but are ready to hand, perfect for all time; this we infer from their unanimity in different persons, even probably in spite of linguistic differences. Whence is our knowledge of this symbolism derived? The usages of speech cover only a small part of it, whilst the manifold parallels in other fields are for the most part unknown to the dreamer; we ourselves had to collate them laboriously in the first instance.