Manuscripts must not have been previously published and, if accepted, are not

to be published elsewhere. They must be typed, doubled-spaced, 70 characters

to a line, on bond paper. The original and two copies must be submitted. The

title must not exceed 150 characters. Footnotes are not encouraged. If necessary,

they should be numbered consecutively within the text and should appear, with

any acknowledgments, on a separate page. Tables and illustrations are not en-

couraged but will be accepted when necessary for the presentation of ideas.

They should be submitted as clear, glossy photographs not larger than 8V2x 11

inches when mounted. The extra costs of illustrations, tables, and mathematical for-

mulas will be billed to the author. References should include, in order: authors,

journal abbreviation (according to the Index Medicus), volume number in arabic

numerals, first page of article, and year. Book references should give author or

editor, title, page cited, edition number, city, publisher, and year. All references

should be checked with the original publications and arranged in order of cita-

tion. In the text, indicate references by numbers in brackets, each number refer-

ring to only one paper. For examples of correct style, refer to a current issue of

this journal.

The following type of abbreviation should be employed: gm, mg, cm3, m, cm,

mm, /.t, /~ p., C, meq. When an abbreviation is peculiar to any field of biology or

medicine, it should be defined by enclosing the complete word in parentheses

following the first use of the abbreviation.

Changes in proof which are other than minor will be billed to the author.

Offprints may be ordered before publication according to a schedule of prices

accompanying the galley proof of the article.