(1) Three kinds of chlorophyll mutants (chlorina, basi-viridis II and virido-albina) and three others, morphological mutants (early, slender and irregular-ear) of einkorn wheat were subjected again to gamma- and X-rays. Their radiation susceptibility was examined in X₁ and in X₂-seedlings.
(2) Radiation sensitivity of mutant strains in the X₁-generation, concerning germination or survival rate, plant height and fertility was not much different from that of the normals.
(3) In the X₂-generation the frequency of chlorophyll mutation in mutant strains was the same when their germination rate was good. On the contrary, it became low, when the percentage of non-germinating heads was high. Addition of radiation injury or additional gene mutation might be the cause of the variable viability in the X₂.
(4) Mutation spectrum of the mutated strains seems to be similar to that of the normal strain. About half of the chlorophyll mutants were albina.
(5) Mutations in one major gene seem to bring about a similar response to radiation as that of the normals.

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The cytological effects induced by the water extract from Cicuta virosa L. on the meiotic divisions in A. victorialis L. subsp. platyphyllum Hultén have been studied.
The most outstanding noxious effect on this water extract is occurredce of stickiness and clumping of chromosomes in meiotic divisions.
The sticky bridge, lagging and fragmentation of chromosomes at 1st and 2nd anaphase were found. And also, the alveolation at interkinesis could be observed (periods of treatment: 20 hrs.).
A. victorialis L. subsp. platyphyllum Hultén was strong and rapid.

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The cytological effects of water extracts prepared from Arisaema japonicum and Chelidonium majus have been studied with root tip cells of Trillium kamtschaticum and ovular tissue cells of Paris tetraphylla.
Arisaema extracts were prepared by immersing 25 grams of roots and bulbs into 100cc of tap water. Remarkable effects of extracts after treatments for 4.5 and 7.5 hours are stickiness of chromosomes at metaphase and sticky bridges at anaphase or telophase. In addition to these anormalies, the occurrences of pseudochiasmata at anaphase and of lanky chromosomes at metaphase were recorded. Chelidonium extracts were prepared by immersing 25 grams of the whole plant into 100cc of tap water. Cells treated with extracts for 4.5 and 7.5 hours showed the stickiness and clotting of chromosomes.

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1. In the present research, the germination of F₂ seed, and the external characteristics, fertility and the number of somatic chromosomes of trigeneric triple F₂ hybrids (TperHRF₂) raised from (Triticum persicum×Haynaldia villosa F₁)×Secale cereale were studied.
2. 113 grains of F₂ seed were obtained from 18 F₁ individuals which were shown partially fertile, and all of the seed were sown in separate pots in October 1958 and 97 grains germinated and 87 of them matured (Table 1). The germination of F₂ seed varies with the each parent, and the percentage of germination has been shown to vary from 50 to 100 for the seedlings, or from 0 to 100 for the matured F₂ plants (Table 1).
3. As seen in Table 2, the number of somatic chromosomes of the 89 individuals of TperHRF₂ hybrids was found to vary from 38 to 58.
4. Some individual differences were observed in the external characteristics of the F₂ plants, even among the plants having the same number of chromosomes (Tables 3 and 4). The culm length of almost all of the F₂ tended to be inferior to that of the parental plant (F₁). And there seems to be no correlation between culm length and the number of chromosomes. The length of spikes and the number of spikelets per spike, in general, were superior to those of the parent (F₁), excepting some individuals which were somewhat inferior to those of the parent. The length of awns, the most of the F₂ which were raised from F₁ having 2n=26 chromosomes were superior to those of the parental plant (F₂), but in the other ones it was in general that they tended to be inferior to that of the parental plant (F₁). The spikelet density of the most of F₂ which were raised from the F₁ having 2n=28 chromosomes were superior to those of the parents (F₁), while in the remaining all the others were the same value or inferior to that of the parents. Generally speaking, the external characteristics of F₂ plants were somewhat inferior to that of the parental plants (F₁).
5. The external appearance of spikes of F₂ plants having 2n=38-46 chromosomes violently revealed rye characteristics more than that of Haynaldia and wheat, ond those other ones having 2n=47-56 chromosomes resembled more closely Haynaldia or wheat, because there are the differences of consisting of chromosomes between the former group and the latter.
6. As can be seen in Table 5, 21 in 69 F₂ plants show fertility though under natural selfing conditions it is not such a high percentage. And those values are progressively exceeding those of parental plants (F₁)

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