14 INHERITANCE IN SILKWORMS, I 



(564) white X Galbin Italiano race, white larva, producing all 

 white. 



(440) moricaud X Japanese Green race, white larva, producing 5 

 moricaud and 3 white. (Lot so reduced by disease as to make numbers 

 of no significance.) 



(563) white X Italian Salmon race, tiger-banded larva, producing 

 135 tiger-banded, 62 white and 2 moricaud. 



(343) white X Italian Yellow race, white larva, producing all 

 white. 



(441) moricaud X Japanese White race, patterned larva, produc- 

 ing 45 moricaud and 46 patterned. 



(468) moricaud X Istrian race, white larva, producing 120 

 moricaud and 154 white. 



(475) moricaud X Persian Yellow race, white larva, producing 17 

 moricaud and 19 white. 



These few rearings show that moricaudness in larvae is a dominant 

 Mendelian character, and whiteness a recessive. In all the outmatings 

 with other races than the Bagdad (Nos. 564, 440, 563, 343, 441, 468 and 

 475) the Bagdad moricaud must have been a cross-bred (heterozygote) 

 individual. 



I have had a single moricaud larva appear in a lot of white 

 Chinese Cross race, and a single one in a white Galbin Italiano race. 



In 1904 a single larva in a lot of 100 (race unknown) appeared of 

 a "remarkable warm tawny brown clouding over the whole body, the 

 skin being everywhere strongly dotted and finely lined, the spots and 

 lines being a warm brown instead of a blackish brown or blackish lead 

 color characteristic of other moricaud sports." 



In some lots of larvae reared (experimentally) under conditions 

 of extreme humidity from time of hatching to pupation, a marked 

 tendency toward an abundant fine dotting, aggregating into short 

 curved lines was shown, so that the bodies of the worms had a very 

 noticeable blackish or moricaud appearance. 



A detailed study on extensive scale of the inheritance behavior of 

 moricaudness is being made in our laboratories by Miss McCracken. 



Tiger-banded or Zebra type. — The tiger-banded or zebra larval 

 type (PI. I, fig. 2, PI. Ill, fig. 2) is a perfectly distinct and strongly 

 marked type and appears as a regular dimorphic, or better, dichromatic, 

 larval variant in the Italian Salmon race. In relation to the unstriped 

 or white type it is dominant in the Mendelian sense and usually be- 

 haves with almost perfect regularity in conformity with Mendelian 



