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OFFICERS 1979, 1980 DIRECTORS Jack Mauritz, President Dr. John E. Haaland, Past-President Director, Hennepin County Pillsburv Co. Park Reserve Distr ~ ct, Box 296 Vice President, Environmental Affairs Maple Plain, MN. 55359 Minneapolis, MN. 55401 Dr. James R. Johnsol\ President-Elect Dr. Kathleen M. Keenan ~otvllf.d ol tM 3M Company 16-236 a H. Sci. Unit A St. Paul, MN. 55101 University of Minnesota Steven Ethen, Secretary'Treasurer Minneapolis, MN. 55455 Burnsville High School Dr. Wayland Lee Ezell MINNESOTA Burnsville, MN. 55337 St. Cloud State University St. Cloud, MN. 56301 EXECUTIVE Dl RECTOR Dr. L.D. Fren~~l University of Minnesota M.l. Harrigan ACADEMY St. Paul, MN. 55108 Pioneer Building, Room 410 Dr. Richard W. Fulmer St. Paul, MN. 55101 Cargill, Inc. Research Cargill Building OF SC-IENCE OFFICERS OF THE Minneapolis, MN. 55402 JUNIOR ACADEMY Dr. Edmund Hibbard Dr. William C. Bessler, Director Environmental Biologist Affiliated with Mankato State University Northern States Power Co. The American Association Mankato, MN. 56001 Minneapolis, MN. 55401 for the Mrs. Karin Ostrand, Director-Elect Dr. Wendell Mordy Advancement of Science Harding High School Science Museum of Minnesota St. Paul, MN. 55106 St. Paul, MN. 56101 E. William Anderson, Past Director Dr. William 0. Peterfi. Mound Westonka High School University of Minnesota, Morris Mound, MN. 55364 Morris, MN. 55267 Joseph Sizer MINNESOTA SCIENCE Minnesota State Planning Agency TEACHERS ASSOCIATION Capitol Square Building Theodore G. Molitor St. Paul, MN. 55101 Volume 46 Alexander Ramsey High School Dr. Phillip G. Thompson No.1 Roseville, MN. 55113 Morrill Hall 1980 University of Minnesota EDITOR Minneapolis, MN. 55455 Angelo Cohn Dr. Wayne Wolsey Pioneer Building, Room 410 Macalester College St. Paul, MN. 55101 St. Paul, MN. 55105

EDITORIAL ADVISORY COMMITTEE CHAIRMAN AQUATIC BIOLOGY GEOGRAPHY Dr. Patricia B. Swan Calvin Fremling Dr. David Lanegren University of Minnesota Winona State University Macalester College St. Paul, MN. 55108 Winona, MN. 55942 St. Paul, MN. 55101 EARTH SCIENCES PLANT PATHOLOGY H.E. Wright Dr. David French University of Minnesota University of Minnesota Minneapolis, MN. 55455 St. Paul, MN. 55108

"The purpose of the corporation shall be: The advance the presentation and discussion of scientific matters; to ment of pure and applied science through the fostering of publish scientific papers; to encourage research and education research, education, and understanding; to provide an or in science for public good; and to engage in such related ganization of persons engaged or interested in science, activities as may be deemed proper." especially in the state of Minnesota; to hold meetings for The Academy of Science is a non-profit organization.

Published by the Minnesota Academy of Science, Suite 410, Pioneer Building, St. Paul, MN. 55101. Annual membership in the Academy is $15.00, Graduate Students, $3.00; Undergraduate Students, $1.00, which includes receipt of the journal.

The Minnesota Academy of Science is affiliated with the American Association for the Advancement of Science.

Editorial correspondence should be addressed to The Editor at the Academy address. Table of Contents

Glacial Drift Stratigraphy; Ultrastructural Features of Spicules New London-Spicer Area, Minnesota 6 of Five Species of Minnesota Sponges 13 ... D.B. ANDERSON, L.G. SOROKA ... LOUISE A. ROLLINS, LYNN D. HYLAND

Acid Rains: Implications A technique for Collecting Water Samples for Minnesota Agriculture 9 Under Extreme Winter Conditions 16 . . . PRABHU D. RAWATE ... JOHN B. CARLSON, GEORGE E. AHLGREN

Use of Peat Hydrolysate for Cultivation Observations of Diatom Populations of the Yeast Candida Utilita 10 in the Snake River, Minnesota 18 ... JEFFREY B. DENNY, ALLEN G. GOOD ... DONALD G. KADDATZ, KEITH M. KNUTSON

COVER AND SPECIAL PHOTO SECTION - The scene in the hall of competitive science exhibits at 1980 Minnesota ISEF, the International Science and Engineering Fair at the St. Paul Civic Center, for which the Minnesota Academy of Science was sponsoring host. On Page 2 prize winners are seen on stage to receive their scholarships and special awards. The Page 3 picture shows the public entrance to the displays of young scientists. Close-ups of some of the almost 500 entrees are shown on Page 4. (Further details below and inside).

Jack Mauritz, 1979-1980 president of the Minnesota Academy of Science, presents the Academy's plaque for distinguished service to Robert Adams, a vice-president of 3M Company, who served as general chairman for the 1980 ISEF. (Minnesota Governor AI Quie is shown on Page 5 as he signed the proclamation of Science and Technology Week in advance of ISEF and the State Science Fair that preceded the international event.)

The Minnesota Academy of Science does not take a stand on issues which may be discussed in articles published in the Journal. Readers should bear in mind that views expressed in these articles are strictly those of the authors.

Journal of, Volume Forty-six, No. 1, 1980 1