1. One triploid hybrid, Avena barbata×strigosa, two pentaploid hybrids, A. barbata×fatua and A. barbata×sterilis, four hexaploid hybrids, A. fatua×sativa, A. fatua×sterilis, A. sativa×byzantina and A. sterilis× byzantina, and their parents were studied morphologically and cytologically.

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(1) KONDO, K., 2) who was at Ibaraki Prefectural Agricultural Experiment Station, found a fact that a small quantity of non-glutinous rice seeds were born mixedly among glutinous ones in every generation on the plants belonging to a line of the glutinous variety called “Aikokumoti”. A few lines of these samples were delivered to the writer and were tested by means of the pedigree culture for three years from 1926 to 1928, and the following results were obtained.
(a) The line of glutinous variety“Aikoku-moti”produced in every generation a small quantity of non-glutinous seeds, whose percentage was 0.67 in 1926, 0.16 in 1927, 0.29 in 1928 and 0.44 in total, showing a wide variation among families (M±σ=1.01±1.08 in total). And a trend was found that the percentage of the nonglutinous mutants was rather high in the highly sterile families.
(b) All of the non-glutinous mutant seeds (180 1) grain in total) occurred on the glutinous plants, produced in the next generation two kind of seeds, the non-glutinous and the glutinous, in the ratio near to 3:1, showing that all of these mutants were heterozygous for the endosperm character, and that the non-glutinous was dominant over the glutinous.
(c) In the next generation of the non-glutinous seeds born on the non-glutinous mutants, the segregating and the constant non-glutinous families appeared in the ratio near to 2:1, the percentage of the constant families being 31.59 (D/P.E.=0.89 as 34%).
(d) Although the segregation ratio in the above segregating families was also near to 3:1 (the percentage of the glutinous =23.78 in total), a small deficiency of the recessive glutinous seeds was observed as a whole in concidering the deviation, which was much larger when the theoretical percentage was taken as 25% (D/P.E.=10.58) than when it was taken as 24% (D/P.E.=2.25). This ratio showed also a wide variation among families (M±σ=23.77±3.30), the percentage of the recessive being abnormally deficient or excessive in some families.
(e) In the progeny of the constant non-glutinous families derived from the non-glutinous mutants, there appeared no glutinous seeds, showing that reversion did never occur in this case.
(f) The pollen in the flowers of the glutinous plants was tested by iodine reaction, and it was found that a small percentage (1.04%) of the non-glutinous pollen grain was mixedly produced (see figure on page 60).

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In the present paper a case of linkage of sex-chromosomes with autosomes is described. The observations are made exclusively from pollen mother cells of an male plant of Humulus japonicus SIEB et ZUCC. which was cultivated in Hokkaido (Northern part of Japan). This male is pure in its sexual expression, but unusual as to the behavior of sex-chromosomes. The results are summed up as follows:
(1) There is one pentapartite chromosome complex in the diakinesis beside 6 normal bivalents. From the comparison of this unusual male with normal males, it is clear that this pentapartite complex is formed as the result of the end to end union of the sex-chromosomes (Y₁XY₂) and an autosome pair(ss). This pair of autosomes is one of the smallest elements of 7 bibalents of the normal male.
(2) The multiple chromosomes are united in the order Y₁ ss XY₂ (Fig. 1 and 2).
(3) In the heterotypic metaphase we see W- or N- shaped arrangement of the pentapartite complex (Fig. 3 and 4). From the latter arrangement two kinds of gametes are expected, namely 6+s+s+Y₂ and 6+X+Y₁.
Very often we see modifications owing to the separation of the linked elments. In Figs. 5 and 6 two cases are shown, in each of these the complex is divided in three parts Y₁, ss and XY₂. In this case we can expect four kinds of gametes, namely 6+s+X, 6+s+Y₁+Y₂, 6+s+Y₁+X and 6+s+Y₂. In Figs. 7 and 8 the complex is divided in two groups Y₁ s and sXY₂.
Further we can clearly see an unequal pair sY₁, and a large pair XY₂ in Fig. 9, where one s-chromosome is cut off by the knife.
(4) The second division is equational. We can see two kinds of the daughter plates, one with 8 chromosomes and the other with 9.
(5) Fertility of pollen grains was not studied.
(6) The validity of the new interpretation of WINGE (1929) on the sex-chromosomes ofH. japonicus, that 3X's determine the male while 2X's the female, is discussed.

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Morphological characters of various F₁ hybrids between Triticum-species are described, which were provided by the writers during the past eight years chiefly for cytological investigations. The grade of fertility is also given in some hybrids.
The most noteworthy hybrid plants are the ones between T. aegilopoides and T. dicoccoides and its reciprocal. They are less than 30cm in height and completely sterile. They look like T. dicoccoides, but slender and very short. The culm of this hybrid does not tiller at all, having always a single culm. The head consists of 4-5 spikelets and is very fragile.
The results of crossing experiments are given in Tab. 1. and the spikes and the whole plants are in illustrated Pls II-IV.

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