This reproduction was made from a copy of a manuscript sent to us for publication and microfilming. While the most advanced technology has been used to pho tograph and reproduce this manuscript, the quality of the reproduction is heavily dependent upon the quality of the material submitted. Pages in any manuscript may have indistinct print. In all cases the best available copy has been filmed.The following explanation of techniques is provided to help clarify notations which may appear on this reproduction.
Manuscripts may not always be complete. When it is not possible to obtainmissing pages, a note appears to indicate this.
When copyrighted materialsare removed from the manuscript, a note ap pears to indicate this. 3. Oversize materials (maps, drawings, and charts) are photographed by sec tioning the original, beginning at the upper left hand comer and continu ing from left to right in equal sections with small overlaps. E)ach oversize page is also filmed as one exposure and is available, for an additional charge, as a standard 35mm slide or in black and white paper format.* 4. Most photographs reproduce acceptably on positive microfilm or micro fiche but lack clarity on xerographic copies made from the microfilm. For an additional charge, all photographs are available in black and white standard 35mm slide format.*
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.