Abstract
In Bombyx mori, as in Drosophila, larval optic discs could be successfully transplanted to different larval hosts. The results are summarized as follows:
From my results, we may postulate the presence of the r+ substance in black type, in addition to the W(w+) substance whose existence has been postulated by KIKKAWA ('37) and KAWAGUCHI and KIN ('37, 38). The r+ substance acts only in the presence of W gene.
Implanted eye discs usually show deeper pigmentation in the female hosts than in the male.
During the course of this experiment some fragmental eyes were discovered. When the fragments are found in one host besides a seemingly entire eye, the former shows usually lighter color than the latter.
