Effect of Light Conditions on Hatching of the Silkworm Egg, Bombyx mori L.

Using silkworm eggs, we investigated effect of light on hatching.1. The hatching mode could be divided into five fundamental types, i.e., constant light, constant dark, dark to light and light to dark I, II types.2. Under constant light, the hatching mode of embryo was exhibited as a gently sloping peak for 2 days, while exhibited as an acute peak under constant dark.3. Induction of eating egg shell of embryo depended upon switch-on the light after the darkness of more than 3 hr, but, without switch-on, the eating egg shell was inhibited for a certain length of time under constant darkness.4. The darkness of more than 3 hr was necessary for embryo to do the effective response for hatching.5. Considering these results, some discussions were made on the hatching mechanism in the five fundamental hatching types.