ALTERNATIVE INHERITANCE. 



Larval Color — Pattern, 



The larval color pattern types that show alternative inheritance 

 are four: (i) moricaud or "darky" (PI. Ill, figs. 4, 8); (2) tiger- 

 band or zebra (PI. I, fig. 2, PI. Ill, fig. 2) ; (3) patterned (PI. I, fig. 4, 

 PI. Ill, figs. 3, 7), and (4) white (PI. I, figs, i, 7; PI. Ill, figs, i, 5). 

 The white type shows several sub-types which are, however, of the 

 nature of fluctuating variations (see p. 40). Of these types the mori- 

 caud is a melanic sport which has appeared in three different races in 

 our laboratory; the tiger-banded is a dimorphic (or better, dichro- 

 matic) form of the Italian Salmon race ; the patterned is characteristic 

 of the Japanese White and other races, and the white is characteristic 

 of the Bagdad, the Chinese White, the Istrian and other races. 



Moricaud type. — In 1904 the first examples of moricaud larvae 

 appeared in the laboratory. Two moricaud individuals appeared in a 

 lot of Italian Salmon race (eggs received from Sondrio, Italy). One 

 of these died as larva ; from the other a male moth was obtained. This 

 was mated with a female of Chinese Cross race (white larval type). 

 The offspring were, as to larval character, equally divided between the 

 paternal (moricaud) type and the maternal (white) type. There were 

 no intergrades. In the second generation rearings all the larvae derived 

 from mating moths of white larval type together were white, while in 

 cross matings, i. e., moricaud larvae with white larvae, lots were ob- 

 tained composed of moricaud larvae and white larvae without inter- 

 grades. On account of disease the lots were too small to give the 

 numbers of each kind of larva any value as revealing the true numerical 

 relation of the two types. 



In 1905 a single moricaud larva appeared in a Bagdad (white 

 larva) lot. This larva produced a female moth, which was mated with 

 a male Bagdad (from white larva). The young (1906) of this mating 

 were 154 white larvae and 153 moricaud larvae with no intergrades. 

 Ten second generation lots were reared (in 1907) by making the 

 following inbred pure and cross matings: 



(536) moricaud X moricaud, producing all moricaud larvae. 



(444) white X white, producing all white larvae. 



(470) white X moricaud, producing 11 white larvae and 5 mori- 

 caud. (Lot so reduced by disease as to make the numerical proportions 

 of no significance.) 



