LETHAL ACTION OF X-RAYS ON EGGS OF THE SILKWORM, BOMBYX MORI L.

The present writer X-rayed eggs and female moths of the silkworm and obtained the following results. (1) Irradiation of X-ray s induces lethal effect on embryos in the eggs. With increase of dosage, the uniformity of developmental processes of the embryos become disturbed, and the percentage of unhatched eggs increases proportionally. (2) Lethal effect takes place usually at the end of the embryonic stage, but a few eggs of each treated series hatch out, even when exposed to a considerably large quantity of X-rays. (3) The effect of X-rays was slightly stronger in the younger eggs than in the older. (4) If the percentage of unhatched eggs in a irradiated series, which is corrected on the basis of that of the control as 0.00 per cent, is represented by x (per cent) and dosage of X-rays at that time by r (r unit), the relation between these two variables may be shown by the following formula: (snip)出庫直後の越年卵, 交尾前の雌蛾竝に浸酸處理後1日目の蠶卵に種々の量のX線照射を行ひ, 次の結果を得た。1) X線照射の刺戟は蠶卵に對し致死的影響を及ぼし, 照射量の多きに從ひ胚子の發育不揃となり, 死卵歩合は増加する。2) 多量照射の場合でも照射區中の極く少數のものが孵化する程度の照射量であれば, 死卵は殆ど催青死卵である。3) 熟度を異にする卵にあつてはX線致死作用は幼若なるものに於て大であるが, その差は僅少である。4) 對照區の死卵歩合を0.00%(孵化歩合100・00%)としての照射區の死卵歩合をx%とし, その時の照射量をr(r單位)とすれば, 次の關係式が成立する。(省略