Studies of the adult morphology of male D. melanogaster suggest that a shortening of body parts is the common aspect of the pleiotropic effects of fj (four jointed tarsi) on the development of the leg, wing, scutellum, distal parts of antenna, and one of three tergite segments measured. In the scutellum and distal antenna the only detected effect of fj is overall shortening, whereas local effects appear in leg and wing. Shortening of the leg is maximal (44%) at the proximal tarsal segments and absent at the distal two, confirming earlier studies. In the wing, total length is reduced 10% and maximum shortening (50%) occurs in the area between the anterior (ACV) and posterior (PCV) cross veins, while the proximal longitudinal veins are longer or unchanged. The effect of fj on wing width is small. Observations on cell density and bristle spacing also indicate that the strongest effect of fj is in the central area, between the ACV and PCV. We interpret the primary effect of fj to be a general reduction in the longitudinal growth pattern of many different imaginal discs. Secondary effects in the leg include a change in tarsal segmentation, followed by a bristle pattern change. In the wing, the angle of veins, bristle pattern on the subcosta vein, positions of ACV and PCV, and cell density variations are secondary effect of fj. A decrease in cell density on the wing surface between ACV and PCV may be related to a final stretching of wing tissue after the process of vein formation. Local effects are not seen in other discs which lack sequential regional patterning mechanisms emphasizing the effects of general shortening. The similarities in developmental aspects between leg and wing are discussed in relation to homoeotic changes by certain mutants.

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Hypo-pentaploid Triticale with four B chromosomes (2n=33+4B′s) derived from (Triticum durum×Secale cereale with 2B's) ×T. durum was cytologically studied, particularly on the normal chromosome component and on the behaviour of B chromosomes.
As a result of Giemsa staining for meiotic metaphase in pollen mother cells it was made clear that the normal chromosome component in the present Triticale consisted of 27 chromosomes of T. durum and 6 ones of S. cereale. The present Triticale showed a highly disturbed meiotic pattern. At MI the modal configuration of chromosomes was found in 12II+9I+2BII. At AI the unequal distribution in number and the many lagging chromosomes were observed, but the micronuclei at tetrad were a small number.
The number of B chromosomes in the present Triticale, BF1 plant, was twice as many as F₁ parent. This indicates that in Triticale the nondisjunction of B chromosomes also takes place as well as in the original rye plant. The degree of multivalent formation between the B chromosomes was much lower in the present Triticale than in the original rye plants with 4B's. This indicates that the meiotic pairing of B chromosomes is disturbed by the change of genetic environment.

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An electrophoretic survey of up to forty presumed isozyme loci was carried out in Asian and African cultivated rice (O. sativa and O. glaberrima) and in weedy and wild forms of African O. breviligulata on a total of 1, 948 strains. Hidden variability was checked by a test of heat stability at thirty isozyme loci in the same species.
The mean gene diversity index ("heterozygosity") was high (0.23) in O. Sativa, medium (0.14) in wild O. breviligulata and low (0.06 and 0.03) in weedy O. breviligulata and O. glaberrima.
In contrast, a maximum of seven alleles at a single locus could be distinguished in wild O. breviligulata while only three at the most were found in O. sativa and two in O. glaberrima and the weedy forms of O. breviligulata.
Calculations of genetic distances showed that the cultivated, wild and weedy African species formed a genetic group distinct from O. sativa. Multivariate analysis of the data on an individual strain basis confirmed this fact and showed in turn that most varieties of O, sativa tended to cluster in two groups which correspond to the so-called Indica and Japonica subspecies. There was however a continuous array of intermediates between the two groups.
Multivariate analysis also showed that the endemic African strains with the most genetic affinity to O. sativa were certain strains of the weedy form of O. breviligulata.
Analysis of F₁ pollen sterility among 115 strains of O, sativa permitted the extraction of one small Indica and one small Japonica group of strains characterized by a high pollen sterility relationship but most strains were intermediate.
Each group had little gene diversity, with more than 80% of the loci fixed for one allele. Their isozyme patterns were remarkably complementary in that most of the various gametic associations of alleles found in the numerous intermediate strains could be explained by hybridization between varieties belonging to one and the other group. Consequently, these were assumed to represent the ancestral isozyme patterns of the Indica and Japonica subsp.
Similar genetic distances, which point to a divergence time of one to a few millions years ago were found between O. glaberrima and the ancestral types of Indica and Japonica in the three combinations.
Assuming the neutral theory of isozyme polymorphism, the data confirmed that O. glaberrima was domesticated from O. breviligulata independently of O, sativa. They also suggest that, at the origin of O. sativa, the Indica and the Japonica types were also domesticated independently. The large diversity of O. sativa would result: (i) primarily from introgressions that occurred between the ancestral cultivated types, together with the selection imposed by man, and (ii) secondarily, following the dispersion of cultivars, from the introgression of genes of wild rice in various areas. Some of the weedy forms of O. breviligulata could have originated from natural hybrids between the two cultivated species, O. sativa and O. glaberrima.

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Variation of chromosome number and constitution in the callus cells of Luzula elegans Lowe (syn. L. purpurea Link.) (2n=6) was investigated. The chromosomes of the plant have nonlocalized kinetochores. Callus was induced and subcultured on the basal medium of Linsmaier and Skoog (1965) with 3.0mg/l of 2, 4-D and 300mg/l of casein hydrolysate, and with 3.0mg/l of 2, 4-D and 1g/l of yeast extract. The ratio of increase in fresh callus weight was about three and a half times after two months of subculture on the medium with casein hydrolysate. The ratio of increase on the medium with yeast extract was larger than that on the medium with casein hydrolysate. Aneuploid cells and new type chromosomes were observed. Most new type chromosomes were medium-sized fragment and dot chromosome.

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A highly reproducible method for differential staining of the centromere regions of plant chromosomes was reported. In all of the fifteen plant species used, the centromere regions of metaphase chromosomes were differentially stained. The method, which was proposed to call "HCl-Ag-I method", comprised of the fixation with glacial acetic alcohol, the enzyme maceration and flame-drying, the treatment with 0.2N HCl, and the incubation in 50% aqueous solution of AgNO₃. The chromosomes stained with the present method were least damaged, and their morphological features were preserved well.

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Three Chinese hamster stocks were established having a reciprocal translocation in a homozygous state from males irradiated with 400R X-ray. Morphological changes allowed to easily identify two translocation chromosomes in T(1;2)9Idr, but only one of them in T(2;10)3Idr and T(2;8)5Idr without banding. Both males and females heterozygous for each translocation were semi-sterile, whereas homozygotes were fully fertile.

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In the developmental analyses of Drosophila mutants, it is necessary to distinguish mutant embryos from heterozygous or normal ones.
We have developed an enzyme marker system by means of an X-linked mutation Zwischenfermentⁿ (Zwⁿ). By histochemical staining for the activity of glucose- 6-phosphate dehydrogenase (G6PD, E.C.1.1.1.49) in a single embryo culture, Zwⁿ cultures were distinguishable from Zw⁺ ones.
The applicability of the method to the analysis of the X-linked developmental lethals was demonstrated by examining the cell differentiation in vitro of an embryonic lethal mutation l(1)EI43. A morphological abnormality was found specifically in the cultures from hemizygous lethal embryos.

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Ethanol tolerance of D. virilis, measured by the concentration killing 50% of adults (L. C. 50) after two days of treatment is above 10% and only two other Drosophila species are presently known to be more tolerant. D. virilis appears to use some artificial alcoholic resources in beer factories. However, variations of alcohol tolerance do not seem to be so much related to the nature of larval resources but better to latitude of origin. Our data suggest that, for various biometrical traits, genetic latitudinal clines occur in D. virilis as in D. melanogaster and several other Drosophila species.

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