1) Plants or dormant seeds of three different forms of sesame (Sesamum indicum L.) cultivated in Japan, B₁D(BAN-type), WD(3BO-type) and WD₈ (QAN-type), were treated with four different radiations, (β-ray from P³², X-ray, γ-ray from Co⁶⁰, and β-ray+X-ray).
2) Morphologically modified plants and several mutants obtained from the treated plants or from their progenies were compared with the controls as to vegetative and floral organs.
3) Three important morphological changes were observed: Alteration of phyllotaxis, development of nectary to flower or capsule, and alteration of loculus number per capsule by addition of an extra carpel.
4) The extra-floral nectary of Sesamum is homologous to the floral bud; by the radiation treatment, several transitional forms from nectray to flower are obtained.
5) The form B₁D(BAN-type), gives many modified and mutant types and among them there are the same types as 3BO-type(WD) and QAN-type(WD₈), used as the materials in the present study.
6) In certain mutants, there was a greater increase in the seed yield per plant than in that (yield) of the control; therefore, such mutants were marked as beneficial ones (Mutant SM3-20, SM3-22, etc.).
7) The relation between the normal cultivated type and the induced mutant type is discussed from the sesame evolutional point of view, the result proving that B₁D(BAN-type) may be the most primitive type among the sesame forms cultivated in Japan.

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1. Competition experimets between the brown gene and its wild type allele were carried out by using population bells and ordinary culture ottles. The mutant brown gene was almost always superior to it wild type allele.
2. The parental population size of 50 to 150 per generation was sufficient to suppress random gene-fixation and to secure an increase of frequency of the brown genes. Therefore, the adaptive superiority of the brown gene to its wild type allele under experimental conditions was regarded to be considerably high.
3. The following properties of brown homozygote were found and considered as factors of the adaptive superiority of the brown gene in competition experiments.
a) The viability of brown. homozygote increased under high larval population density.
b) The larvae of brown homozygotes grew more rapidly in mixed culture with wild-type larvae than in pure culture.

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1. The eye discs, the wing discs, the cephalic complexes, the leg discs, the haltere discs, and the salivary glands of the mature third-instar larvae (about 96 hours after hatching) of the insecticide-resistant strains (Hikone and WMB) and the insecticide-susceptible strains (Fukuoka and Canton-S) of D. melanogaster were cultured in the synthetic media containing 25.0ppm and 50.0ppm parathion respectively.
2. When 25.0ppm parathion was added to the medium, it was observed after 24 hours culture that the eye discs, the wing discs, the cephalic complexes, and the leg discs of Fukuoka and Canton-S strains were more pronouncedly inhibited than those of Hikone and WMB strains. The haltere discs of all strains were markedly inhibited in the medium containing 25.0ppm parathion. The salivary glands of all strains were less inhibited by 25.0ppm parathion.
3. When 50.0ppm parathion was added to the medium, every organs of the insecticide-resistant strains and of the insecticide-susceptible ones were pronouncedly inhibited after culturing for 24 hours.

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