The balance of references and citations in a single. year indicates one very important attribute of the network . Although most papers produced in the year contain a near- average number of bibliographic references, half of these are references to about half of all the papers that have been published in previous years. The other half of the references tie these new papers to a quite small group of earlier ones, and generate a rather tight pattern of multiple relationships. Thus each group of new papers is “knitted” to a small, select part of the existing scientific literature but connected rather weakly and randomly to a much greater part. Since only a small part of the earlier literature is knitted together by the new year’s crop of papers, we may look upon this small part as a sort of growing tip or epidermal Jayer, an active research front. I believe it is the existence of a research front, in this sense, that distinguishes the sciences from the rest of scholarship, and, because of it, I propose that one of the major, tasks of statistical analysis is to determine the mechanism that enables science to cumulate so ~much faster than nonscience that it produces a literature crisis.