14 J. K. BREITENBECHER. 



for the black mutation on October 22, 1918. She possessed all 

 the characters which were normal for a black female, except that 

 her right elytrum was red. She was mated to a male with tan 

 elytra, but pure for black, and this pair gave rise to 3,416 pure, 

 black progeny. The same result is evident as before ; red was not 

 observed in any offspring, even though they were inbred for four 

 generations ; but red was visible, however, in the original parent 

 because it is a dominant color to black. 



It is next in order to consider the elytral mosaics which mani- 

 fested themselves in a pure, white culture. The last mosaic (Mo- 

 saic 31, Tables I. and II.) described made its appearance on Jan- 

 uary i, 1920, from a culture that was homozygous for the white 

 mutant stock. Her body color and right elytrum were both normal 

 for the white insect, but her left elytrum was black. She was bred 

 to a male normal and pure for white. They produced 1,077 

 homozygous white descendants. This test indicates the same gen- 

 eral behavior relative to dominance. Black is manifested here be- 

 cause it is a dominant color to white. It should be possible also 

 to find among the progeny of a homozygous, white culture both 

 red-white and white-red mosaics, but none were found, because it 

 is almost impossible to keep this stock alive. This is not sur- 

 prising, since only one mosaic was seen during the progress of 

 this experiment. 



Because the tan or wild type is recessive to any of the above 

 body and elytral colors, their mosaics will next be considered. The 

 following dominant mosaics are possible from this type : Tan-white, 

 white-tan; black-tan, tan-black; red-tan, tan-red. Of these possi- 

 ble dominant mosaics three have appeared; the white-tan, tan- 

 black, and black-tan. The others as yet have not occurred. 



Thus far only one individual of the white-tan type has been dis- 

 covered, Mosaic 29 (Tables I. and II.). On July 16, 1919, a re- 

 markable elytral mosaic was found which was different from any 

 of the others. This female had a white, left elytrum and a tan, 

 right one ; her body was normal, however, for the wild type. She 

 originated from a wild culture, and when bred to a wild (tan) male 

 produced 864 wild progeny. White was also visible in this elytral 

 mosaic female because white is a somatic dominant color to tan. 



