1) The Author and his co-workers investigated the hereditary relation of the blood groups in 1595 families and came to the conclusion that the human blood group is hereditary according to the hypothesis of the three heredity units. (Table I)
2) The relation between the blood groups mothers and children was tested. The result is shown in table II and III.
3) The blood groups of the human foetus were tested, and it was proved that no foetus has been known to belong to a blood group contrary to the law of heredity. The group agglutinogen in an embryo can be determined from the second foetal month, but the agglutinins in serum will appear after birth.
4) The Group agglutinogens (A and B) and the group agglutinins were found in the blood of animals as well as in human blood. The sera of animals might be classified into six groups.

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The ovaries of some plants develop sometimes into seed-less fruits as the result of inter-specific pollination. Taking much interest in this phenomenon, the author has studied the behaviour of the pollen tubes in this case with certain kinds of plants.
1) First, the ovaries of egg plants could be grown into seed-less fruits when they were stimulated by the pollen of Petunia violacea, but they failed to do so when the pollen of tomatoes was substituted. When the tube growth of these pollen grains in the styles of egg plants was measured, it was found that the pollen tube growth of Petunia had been faster than those of the tomato (s. Tab. 1).
2) The ovaries of squashes were easily stimulated by the pollen of Calystegia japonica but they received little influence from pollen grains of the common sunflower. Then the germination and tube growth of these pollen grains were compared. The pollen of C. japonica germinated easily on the stigmas of squashes and penetrated deep into their styles. The pollen of the sunflower, however, almost failed to germinate on the stigmas of the squash, and when they should germinate the growth of their tubes was very poor in the styles of the latter (s. Tab. 5).
3) The pollen grains of P. violacea have able to stimulate the pistils of egg plants as above stated, but they did not do so in the case of the pistils of Solanum Gilo. Then the tube growth of the pollen of P. violacea in the styles of these kinds of pistils were measured. The results showed that the pollen tubes grew faster in the styles of egg plants and slower in the styles of S. Gilo (s. Tab. 2).
4) The germination of the Petunia pollen was tested in several artificial media. It was found that the germination percentage of the pollen was much higher in the media containing the stylar juice of the egg plant and much lower in that containing the juice of S. Gilo.
5) The tube growth of the Petunia pollen in the grafted pistils were measured. The pollen tubes grew faster in the styles of S. Gilo grafted upon the ovaries of egg plants and much slower in those grafted upon the ovaries of their own plants (s. Tab. 4).
These results may be safely concluded as follows: (a) When the pollen tubes were able to penetrate deep into the style, they made the ovary develop into a seed-less fruit. (b) When the pollen tubes were inhibited in their growth in the style, they failed to stimulate the ovary to develop into a seed-less fruit. (c) The growth of pollen tubes seems to be influenced by some special substances in the style. (d) These special substances seem to the author to be produced originally in the ovary and then go up to the upper portion of the pistil as far as the egg plant and S. Gilo are concerned.

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1. The gametic chromosome number in the normal Portulaca grandiflora is 9 as already stated by TJEBBES, and the somatic number is 18 (Fig. 18).
2. Two haploids were found among 168 F₂ interspecific-hybrids (Magenta No. 22×Orange No. 35) in 1931, next year one haploid was obtained from 100 F₃ plants. Their parents were normal morphologically and cytologically. These haploids are of about half the stature of P. grandiflora with all organs proportionally smaller.
3. There are 9 univalents in the first maturation division of P. M. C.. The 9 univalents are separate in the possible assortment of 1 and 8, 2 and 7, 3 and 6, 4 and 5 (Tab. 1). Sometimes 1-3 lagging chromosomes are observed (Figs. 2-5).
4. In the homotypic division the halves of dyad chromosomes are distributed with the result that four nuclei are formed all lacking whole set of chromosomes. Accordingly the pollen grains, which are shrunken and empty, have no function (Figs. 6-10, Tab. 2). As far as the present investigation goes, I could not find the assortment of 0 and 9. This assortment is however possible in rare case.
5. Haploid selfed gave no seed at all, and also pollination experiment with the haploid on normal plants was negative, but its reciprocal cross gave 5 seeds. One of them gave a progeny almost wholly of parent type, and has diploid chromosome number of P. grandiflora. This fact apparently indicates that the non-reduction of chromosomes happened in maturation division of E. M. C. of the haploid plant.

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Three new Karyotypes of Rumex acetosa were discovered. These are type VI (10i+2J), type VII (10i+2T) and type VIII (8i+2J+2T) (Table I., Fig. 1.). Accordingly the karyotypes of Rumex acetosa are 8 in all. The geographical distribution of the three karyotypes in Rumex acetosa has been studied. Type I was found to be distributed in the northern part of Japan proper, Corea, Kurile Islands and Formosa, and type II in the middle part and type III in the southern part of Japan proper. Owing to the scanty materials the distribution of the remaining karyotypes (types IV-VIII) can not easily be determined (Fig. 2.).
Meiosis in some hybrids between these karyotypes was studied; some of these showed rather irregular divisions while others were quite normal.
The author has arrived at the following conclusions on the origin of the different karyotypes in Rumex acetosa:-
I. The existence of many triploid intersexes in wild and in cultivated plants plays an important part about the origin of karyotypes. Meiosis is more irregular in the triploid intersex than in the triploid male plant or in other autotriploid plants.
II. Consequently new shapes of chromosomes which were not found in the mother plant were found in the progenies of triploid intersexes (Fig. 3-1).
III. Plants with several fragments of chromosomes were often found in the wild. Usually we observed some large J-or V-shaped chromosomes in these plants (Fig. 3-2). Fragmentation of chromosomes was often observed in the course of PMC divisions of some hetero- as well as euploid plants of this species.
IV. Two plants in which the segmental interchange of chromosomes and simple translocation had occured were found. Both are female so that I could not study the ring of four expected. But judging from the shape of somatic chromosomes I can easily decide which chromosomes have changed. The interchanged chromosomes are shown in dots (Fig. 3-3 F' C', 3-4 B' D').
V. The chromosomes of new shape whose origin is undetermined are labelled with question marks in figures. These chromosomes may be explained as the results of complicated changes of chromosomes in the progenies of triploid intersexes. These structural changes in chromosomes perhaps give rise to the differentiation of karyotypes.

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