On the cause of poor hatching of silkworm eggs washed and brushed down in winter in order to produce the commercial eggs

Abstract

1) In the pravious paper, the author (1951) pointed out that when the hibernating-eggs of silkworm were washed and brushed down to produce loose-formed eggs in winter, hatchability in spring became poor and it was caused by the low-temerature of water for washing. UMEYA said in his book (Characters and Environment) that loose-formed eggs had a tendency to show more reduced rate of hatchabilty when refrigerated at 5.0°C than 2.5°C after the washing.
2) In order to investigate by stochastica the influence of temperature of water in washing and refrigerating temperature after washing upon the hatching of hibernating-eggs in spring, the eggs of C122 and Shk-abura were washed by water of 2.5°C and 20.0°C at various intervals from the end of December to the beginning of March and they were refrigerated at 2.5°C and 5.0°C after washing respectively.
3) It was shown that the main effect of washing was most remarkable and significant (k-abura: C122: 1%) but that of refrigerating temperature was not singificant stastistically by factorial experiment.
4) It was indicated by analysis of variance that there exist significant difference of hatchability and practical-hatchability depending on the difference of washing-period in C122 but did not Shk-abura, but there seemed to be exist respectable difference of hatchability and practical-hatchability in the eggs washed by 2.5°C water.