Materials and Methods

Males of the F2 generation which showed two recessive characters were backcrossed to their gold sisters to determine which carried the sex-limited genes for the mutant tail shapes. The females which proved to carry the sex-limited recessive genes were used to breed pure lines of gold lyre tail, sword tail and pin tail guppies. With the foregoing information proved about guppy hered¬ity, I planned and conducted matings which concentrated three mutations into one pure line. The types of offspring and quantities obtained are shown in the accompanying diagram. As before, the backcross was used to separate the desired females. Summary Inheritance of guppy mutation in these experiments followed the Mendelian Principles of Independent Unit Characters, Dominance and Segregation,Purity of Characters and Random Fertilization.

No X or Y linkage was evident in the inheritance of any of the mutations studied in these experiments. Earlier investigators, principally Winge, claimed to find such linkage in their experiments. It is possible that guppy mutations, although similar in appearance, are not always inherited alike. This may account for the differences in inheritance of these mutations. 3. Mutations for tail shape and basic body color can be concentrated in almost any combination the breeder desires by applying Mendelian Principles of Heredity with correct environmental conditions.

Bibliography Research Papers: Regnier, M. T., 1942. “Masculination des Femmelles de Lebistes Reticulatus sous l’lnfluence de la Pregneginolone.” Compt. Rend. Soc. Biol., vol. 136, pp. 202-203. Singe, O., 1922. “One-sided Masculine and Sex-linked In¬heritance in Lebistes Reticulatus.” Genetics, vol. 12, pp. 145-162. 1923. “Crossing Over between the X and Y Chromo¬somes in Lebistes.” Genetics, vol. 1, pp. 201-217. 1927. “The Location of Eighteen Genes in Lebistes Reti¬culatus.” Genetics, vol. 18, pp. 1-42. Smith, D. C. and G. M. Everett, 1943. “The Effect of Thyroid Hormones on the Growth Rate, Time of Sexual Differenti¬ation and Oxygen Consumption in the Fish Lebistes Re¬ticulatus.” Jour. Exp. Zool., vol. 94, pp. 229-240. Tuchmann, H., 1936. “Action de l’Hypophyse sur la Mor-phogenese et la Differention Sexuelle de Girardinus Guppi.” C. R. Soc. Biol., vol. 122, pp. 162-164. Winge, O. and Eshem Ditlevsen, 1947. “Color Inheritance and Sex Determination in Lebistes.” Heredity, vol. 1, pp. 65-83.

Books: Abbot, C. G. Cold-blooded Vertebrates, Smithsonian Scienti¬fic Series, 1934. Gordon, Myron. Guppies as Pets, New Jersey: TFH Publi¬cations, Inc, 1955. Milne & Milne. The Biotic World and Man, New York: Prentice-Hall, Inc., 1952. Srb and Owen. General Genetics, California: W. H. Freeman & Company, 1957. Whitney, Leon F. All about Guppies, Connecticut: Practical Science Publishing Company, 1952.” GROUP AND INDIVIDUAL PROJECTS FOR ELEMENTARY AND JUNIOR HIGH SCHOOL STUDENTS To illustrate the thousands of interesting projects that can be done with great success by even the youngest students in grade school, two sample lists are reproduced here. The first is a list of science fair projects prepared by the Texas Pan¬handle Science Fair, Amarillo, Texas.

Primary, Grades 1-3, Group Exhibits Only Physical Sciences AC Voltage Generation A Shadow Box to Show Con¬stellations A Simple Windlass Chemistry Magic and Test for Nitrogen Chemistry of Ceramics Clay Modeling Flow of Electricity How Light Is Reflected and Bent. How Much Water Is in the Air? Phases of the Moon Rocks of the United States Steam Turbines Water Has Energy Because It Has Depth What You Can See with a Microscope Evaporation and Rain How Does the Airport Work? How Plastics Are Made How Static Electricity Affects Paper Importance of Iron and Steel Simple Machines That Work for Us Sources of Clothing Spring Constellations What Makes an Airplane Move? The Story of Cotton Processing Biological Sciences Conservation of Wild Flowers Sea Shells Soil Conservation Conservation of Wildlife Ants at Work How and What Animals Breathe

How Peas Grow What Foods Have Starch? Bird Nests Build Healthy Bodies and Sound Teeth Collection of Bird Pictures Regional Wildlife First Aid Is the Best Aid How Long Do Animals Live? How Seeds Travel Fur Bearers Parts of Plants We Eat Plant Germination Prehistoric Animals’ Seed and Plant Study