New Mutants in Sciara and Their Genetic Behavior.

GENETIC BEHAVIOR H. V. CROUSE AND HELEN SMITH-STOCKING Department of Embryology, Carnegie Institution of Washington, Baltimore, Maryland Received January 31, 1938 H E present paper deals with six new mutant characters in Sciara T found in this laboratory. In addition, two mutants are recorded which appear to be identical with or allelic to two of these characters. Of the six, one is an autosomal dominant in Sciara coprophila Lintner, and one a sex-linked recessive in Sciara ocellaris Comstock. The remaining four, including one autosomal dominant, two sex-linked dominants, and one sex-linked recessive, are in Sciara reynoldsi Metz (METZ, in press). Selective segregation of chromosomes has previously been established in three species of Sciara (METZ 1926, 1928, 1929). The present paper establishes selective segregation in two other species; namely, S. ocellaris and S. reynoldsi. The dominant characters were found by the second author among the descendants of flies which had been exposed to radium. The radiation was done a t the Howard A. Kelly Hospital in Baltimore through the kindness of Dr. FRED WEST, to whom we are greatly indebted. Whether the mutations were produced as a result of the radiation cannot be stated definitely, TABLE I Linkage data for the character “Stop” in S . coprophila.