Among those of Edgar Durfee’s colleagues who were familiar with this paper it came to be known as “Little Nemo,” for a reason that will become apparent to the reader. It is taken from his mimeographed Cases on Security, third edition, published in 1938. Possibly it was published earlier but there is a gap in the evidence. It did not appear in the first edition published in 1934 but no copy of the second edition has been located. In a few places its age shows, for example in the reference to Walsh as the author of the most recent text on real property, and it should of course be read with an understanding of the time factor. A few cross-references and passages directed to classroom or other student use have been deleted but these changes are minor. Otherwise, with exception of some bracketed citations, the text is just as it was published. Because of its length it is being published in the Review in two parts.