Abstract
I am in possession of an European race Novi Ligure which segregates occasionally yellow silkworms after the first moult. The yellow silkworm cannot eat the mulberry leave on account of the soft structure of its mouth parts which is perhaps due to the lack of chitinous substance, and consequently dies from hunger. This characteristic cannot be distinguished from the normal before the first moult.
The yellow silkworm is a simple recessive to the normal. The deficiency of the yellow type, which is generally observed, for 3:1 ratio is mostly due to the higher mortality of the yellow type in the larval stage than the normal.
