A classification of everything in the universe, from the smallest thing yet measured, the electron, less than a millionth of a millionth of an inch in extent, to the biggest, a star system of a thousand million trillion miles, was described recently by Prof. Harlow Shapley of Harvard in a lecture at the commerce center of the College of the City of New York. Looking forward to a time when man will be able to measure even smaller things than the electron and larger than the greatest star system, Prof. Shapley explained that he had left the classification "open at both ends." Man, Prof. Shapley said, occupies a very small place in all this system, although, beside an electron or an atom, he is not so negligible, at that. "The survey," it was explained, "aims toward giving perspective. It gives a sane and modest view of man's place in the scheme. "The significance of the classification lies in the skeleton which is afforded all science to bring some measure of order out of the world's present chaotic knowledge of the systems of various kinds. "All systems find a place in this synthesis--atoms, comets and galaxies; man, radiation and the space-time complex. When looked at in this objective way, human beings, and all associated terrestrial organisms, appear only parenthetically in one of the subdivisions of the class of colloidal aggregates." Prof. Shapley discussed the concept of the cosmoplasma. "This," it was explained, "is at once the most mysterious and fundamental part of the universe, and only recently has come under direct experimental study. In brief, it is the substratum of materials throughout the universe, between planets, stars and the galaxies. "It has no obvious systematic organization. Hence it includes such diverse constituents as the high speed shooting stars, interstellar calcium gas and radiation itself. "Though no one has even seen an electron, the smallest thing included in the classification, they have been proved to exist in several ways. They give forth flashes of light that can be photographed. They have caused the bending of X-rays as they pass through a substance." [Illustration: The Readers' Corner _A Meeting Place for Readers of_ Astounding Stories] _Likes the "Corner"_ Dear Editor: This month's issue, May, has the best collection of letters you've ever published. All it lacked was a letter from Bernard J. Kenton, that master of epistles and super-science stories. One of your Readers would like to have "The Readers' Corner" omitted. For heaven's sake, don't take it out! I recognize it as one of the best features of our mag, and whenever I open the covers, turn to it directly after having glimpsed the table of contents and the announcement of the stories to appear in the forthcoming issue.