1. 穗と花の短小なる矮型稻3種 (AAbb, aaBB 及び aabb) と常型稻(AABB)との間で穗と花の分化生長の過程を比較した。
2. 播種後37日頃迄は何れの因子型に屬する植物の穗も未だ分化を開始せず, その生長は緩慢で且つ各因子型の植物間で大さの差異が殆んど認められない。
3. 44日經つと大型の2型 (AABB, AAbb) のものは急激に生長が活発となり第一次分岐を出すが, 矮型の2種では未だ分化せず, その大さも前と大差ない。
4. 50日近くになると凡ての型で早くも第二次分岐が完了する。而してAABB,AAbbの2型では第二次分岐上の花で既に内外兩穎の分化が見られるが, 他の2型では此の分化は未だ明確でない。
5. 60日以前に凡ての型で花の内部の分化が完全に終る。葯, 花絲, 胚珠, 鱗皮等が明瞭に識別される。
6. 上記の時期では矮型の穗長は常型のものよりも著しく短いに反し, 穗上のよく發達した花の大さは各因子型の植物間に大差がない。これは矮型で穗自身の生長抑制は發育の稍々早期に起るに反し, 内外兩穎の大さの差は其の生長期 (この品種では播種後約60日以後出穗迄) に到つて始めて見られるからである。
7. 穗の原基を構成する細胞の大さは穗の發育時期の早晩及び各因子型の植物間に大差が無い。
8. 發育初期に就て見れば, 穗の分化生長に關する常型及び矮型間の相違は, 常型及びこれに近き生長型のものは他の矮型に較べて細胞分裂の旺盛期が若干早く開始されること, 及び其後の生長期に於て細胞分裂がより頻繁に起り細胞數が増加し, 從つて組織の分化が早まるため起るものと考へられる。

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In the winter of 1937, pots of Rhoeo discolor Hance were transfered from the green house (23°C) to the place of 2°C for four hours and then were put back again. Two weeks after treatment, some anthers were found to contain a considerable number of tetraploid PMCs mixed among the normal diploid ones. The chromosome configurations were studied by one 'diakinesis' (Fig. 6) and nine MI (Figs. 2-4 and 7-15) PMCs. They involved univalents, ring bivalents, chains of three or more chromosomes, rings of 4 chromosomes and polyvalents bearing triple terminal chiasmata. They are all similar to those demonstrated by Seitz (1935) in tetraploid Oenothera species. These 4x-PMCs are ascribed to be due to the failure of cytokinesis at the last mitosis in the archesporial tissues which were affected by influence of low temperature treatments. The chromosome configurations observed favor the assumption that Rhoeo is an interchange heterozygote as has been hitherto inferred only from ring configurations.

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In this report two more rare pattern types: aulica (Fig. 1-a, b) and gutta (new name proposed by Prof. T. Komai) (Fig. 1-f, g, h) are dealt with. Both of these are due to the factors (P^Au=factor for aulica, P^G=factor for gutta) belonging to the same allelomorphic series as conspicua, transversifascia, spectabilis, axyridis, forficula and succinea and behave as dominants to succinea.
The heterozygote of axyridis and aulica (P^AP^Au) (Fig. 1-c) and the heterozygote of forficula and aulica (P^FP^Au) (Fig. 1-d) can be distinguished as such from homozygotes. The heterozygote of transversifascia and aulica (P^TP^Au) may be distinguished from transversifascia in that the spot has a concavity on the antero-median side (Fig. 1-e), though in some cases the heterozygote of transversifascia and aulica shows the same appenrance as transversifascia. The distinction between the heterozygote of gutta and axyridis (P^GP^A) and the heterozygote of conspicus and axridis (P^CP^A) and that between the heterozygote of gutta and forficula (P^GP^F) and the heterozygote of conspicua and forficula (P^CP^F) can often made by the fact that the spot is provided with an accessory speck on its antero-median corner, though the speck may be missing in some cases (see Report II, Fig. 1-l, m and Report III, Fig. 1-e). The heterozygote of conspicua and aulica (P^CP^Au), the heterozygote of conspicua and gutta (P^CP^G), the heterozygote of gutta and spectabilis (P^GP^S), the heterozygote of gutta and transversifascia (P^GP^T) and the heterozygote of gutta and aulica (P^GP^Au) can not be distinguished from conspicua; the heterozygote of spectabilis and aulica (P^SP^Au) may shows the same appearance as spectabilis.

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In the present study, the somatic chromosome numbers of about 40 species of the genus Carex have been determined (Table 1). In this Table the chromosome numbers are arranged in the systematic order adopted by Kükenthal. Twenty different chromosome numbers have been found as follows, 30, 34, 36, 38, 42, 48, 52, 54, 56, 60, 62, 64, 66, 68, 70, 74, 76, 78, 84 and 90 (Figs. 1-39). These numbers cannot be generally arranged in a series of multiples, but it is noteworthy that the polyploid relation has been observed in C. multifolia and C. stenantha, namely, 2n=30 and 60 in the former (Figs. 18-19), 2n=34 and 68 in the latter (Figs. 27-28) and that aneuploidy has also been found in C. conica, 2n=34, 38 and 42 (Figs. 16-17). As a rule, the chromosome shape is spherical or elliptical. And the chromosome decreases generally in size as their number increases. In C. pilosa, two individuals having the different chromosome numbers (n=32 and 57) have been detected and it is a very interesting fact that their meiotic chromosomes show the secondary association of different types, namely, in the individual of 32 chromosomes, each two bivalents associate generally with each other and in that of 57 chromosomes, each three bivalents associate together (Figs. 44-45). Such pairing in the genus Carex has not been hitherto reported by any investigator.

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This paper deals with the fasciation experimentaly produced in buckwheat (Tochigi No. 1) by the treatment of seeds with the aqueous solution of heteroauxin.
1. In Experiment I, air dry seeds were soaked in 0.1% heteroauxin solution for 60, 50, 40, 30, 20 and 10 hours (Exp. I-A_??_F); in Experiment II, germinated seeds (having a seminal root of about 2_??_4mm long) were immersed in the same solution as in Exp. I for 40, 30, 20, 10 and 5 hours (Exp. II-A_??_E). In both experiments, the seeds treated with the solution were washed with water, and sown in the field to observe the effects of the treatment. In Experiment III, the germinated seeds, similar to those used in Exp. II, were injected with 0.1% heteroauxin solution at the top, and they were sown immediately without washing. In these experiments, the seed germination and the seeds soaking in the chemical were carried out in a thermostat kept at 25°C.
2. In these experiments, abnormal plants with two opposite leaves on the second node (the one above the cotyledon-node) were met with in very high proportions. Such abnormal plants were classified into 4 types (cf. Table 1), In Exps. I and II, the proportions of the abnormal plants to the total seedlings increased with the length of treatment. In Exp. I, the abnormalities other than (a) type were observed more frequently than in Exps. II and III.
In the cases where the seeds were treated for 40 and 30 hours, Exp. I shows higher ratios of abnormal plants than Exp. II, but in the case where the seeds were treated for 10 hours Exp. II shows higher ratio of abnormal plants than Exp. I; in the case of 20 hours no difference was observed between those experiments.
3. Fasciation occurs in some of the branches grown on the second node of the abnormal plants (Fig. 1). Fasciation is not observed in the branches produced on the successive normal node of the abnormal individuals. It was not observed also in the normal plants. Thus fasciation is always accompanied by the abnormalities.
From the facts represented in Table 2, it seems that the condition which induces fasciation also produces the abnormalities. In Exp. III, fasciation was not met with at all. It seems that the fasciation shows a tendency to appears somewhat more frequently in the abnormal individuals belonging to (b), (c) and (d) types than in that of (a) type.

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