250 PHY8IOLOOICAL GENETICS 



1. The chemism of all areas of one type, < .g., between the dark 

 dements of pattern, is affect eel. The mutant gene acts at a 

 level above the pattern, which is not changed. All mutants, 

 mostly recessive, sometimes sex linked, changing a red-ground 

 color to yellow or a yellow color to white are of this category. 

 Examples: red and yellow Callimorpha dominula (Standfuss, 

 1890; Goldschmidt, 1924a); yellow and white Colias (Gerould, 

 1923); Parasemia (Standfuss, 1897). 



2. Within the given pattern, all elements containing melanin 

 pigment increase simultaneously and restrict the nonmelanic 

 areas. These cases of melanism usually are of the polymorphic 

 type, i.e., typical quantitative steps from beginning to complete 

 melanism are found and a series of additive (polymeric) genes 

 are involved in the production of the different steps. Examples : 

 Melanic polymorphism in C. dominula (Goldschmidt, 1924a); 

 Spilosoma lubricipeda, (Federley, 1920; Goldschmidt, 1924a). 



3. Within a given pattern, the whole pattern is intensified or 

 bleached. Examples: Abraxas grossulariata lacticolor (Don- 

 caster); Argynnis paphia-valesina (Goldschmidt and Fischer, 

 1922). In these cases, one sex-linked (Abraxas), viz., one sex- 

 controlled, gene (Argynnis) is involved. 



4. Within the given pattern, individual elements, e.g., the 

 so-called middle shadow within the symmetry field, increase in 

 regard to melanic scales. 



Recessive or dominant genes may be involved and also sex- 

 controlled behavior. If different genes controlling the same 

 process but for different elements of the pattern are involved, 

 combined and additive effects are produced by combination 

 of these genes but in a different way from the foregoing group. 

 Examples: Lymantria monacha (Goldschmidt, 19216); flour moth 

 (Kuehn and Henke, 1929-1936). 



5. The whole unchanged pattern is overlaid by a melanic 

 pigment. Here belong the frequent simple cases of recessive 

 melanism, also of sex-controlled melanism. Example: many 

 geometrids (T. W. H. Harrison, 1920). Here belong also the 

 cases in which the pattern is unchanged but the whole tint of 

 coloration is changed in degrees from light to dark melanins. 

 Example : the male wings of geographic races of Lymantria dispar 

 (Machida, 1924; Goldschmidt, 19336). Here a series of multiple 

 alleles is involved. 



