110 



PHYSIOLOGICAL GENETICS 



found that counteracts the effect of these dominigenes and is 



probably identical with the gene for black; in addition, the 

 quantitative effecl is different in both sexes. 



In this case, further facts could be found which allow the draw- 

 ing of conclusions upon the phenomenon of dominance (Gold- 

 schmidt and Hoener, 1937). In a former chapter, we reported 

 (page 56) that the series of conditions of scalloping that connect 

 the normal with the vestigial wing may be produced by a series 



1 vq ' 

 "AW 



w 



FSL..Qp-D \no 



QQ Y n 



vgf 



"9 



-i 1 r 



m 



"9 



Q* D . 

 Vw ni 

 Nw 



Nw> 



n 



.BQp 

 no 



™ D - 



yi x ix vni m 



VI v 



IF M JT I 



Nw 



w D 



vg 



no. ■ ni 



ni 



<* no 



'D 



Wild type 



Fig. 24. — Graphic representation of the action of the dominigenes upon the 

 phenotype of heterozygotes and homozygotes of the vg series. (From Gold- 

 schmidt- Hoener, 1937, Univ. Cat. Publ. Zool. 41, Fig. 1.) 



of multiple alleles of vg and the respective compounds. A similar 

 series may be obtained by temperature action upon the vg 

 homozygote (see page 12) and again by temperature or X-ray 

 shock upon the Wild type in the phenocopic experiments (see 

 page 8). It was further reported that the effect of these 

 genes is the production of a degeneration of already formed 

 wing tissue according to a definite pattern and that the degree 

 of scalloping is proportional to the time of onset of the degenera- 

 tive process (page 26). These facts have already been used 

 to derive certain notions regarding the action of the gene, and 

 we shall meet them again in the chapter on pattern (see page 229). 



