14 THE UNIVERSITY OF OKLAFIOMA 



elytral color, but its males were of the wild (tan) type. It 

 was found, however, on breeding these insects that both male and 

 female transmitted white body color. It was found that white is 

 a recessive to either red or black, but a dominant to the wild 

 (tan) type. This order of dominance suggested to the author that 

 these four t)ody and elytral colors (red, black, white, and wild) 

 might be allelomorphs. This proved true for the following reasons. 

 The following arguments, taken from Morgan, and others 

 (1915) are in favor of a mviltiple allelomorph series. It is found 

 that the experiments result as observed for Bruchus for these four 

 factors a multiple allelomorph series. 



1. That mu'.tiple allelomorphus seem to affect the same char- 

 acter. This is true for Bruchus, because each body color red, black, 

 white, and wild or tan, affect the entire body and elytral color. 



2. That an individual may contain only two genes of the 

 allelomorph series. These may be the same gene or different mem- 

 bers of the series. This breeding behavior was manifested in all 

 combinations of these genes ; therefore, this is true for Bruchus. 



3. When any two mutant types of an allelomorphic series are 

 crossed, they give a type that is like the dominant parent 

 'or intermediate, because neither brings in the normal allelomorph 

 of the other, consequently the wild type is not reconstituted. -For 

 these mutants of ours in Bruchus the individuals of the second gen- 

 eration are like the dominant parent in each case. 



4. The strongest evidence of a multiple allelomorph series is 

 that there is no crossing over between the genes because of the 

 nature of the theory, v.'hich demands that such genes occupy 

 the same locus. In the thousands of offspring produced by means 

 of various tests no crossing over was observed l^etween the four 

 body colors of Bruchus. 



In all these four respects the mutants (red, black, and white) 

 of Bruchus fulfill the requirements of a multiple allelomorph series. 



SUMMARY 



1. This paper demonstrates the genetic behavior of the inheri- 

 tance of four body and elj^tral colors in Bruchus quadrimaculatus. 



2. The experiments prove that any one of the four color factors 

 can be an allelomorph with any other factor for body color. The 

 order of dominance is red, black, white, and wild or tan. 



3. The tests prove that the four factors (R, Rb, Rw, and r) 

 for the four body colors — red, black, white, and tan constitute a 

 multiple allelomorph system. 



4. It is also proved that this allelomorphic series is a sex- 

 limited one and not sex-linked, because every male was tan. 



