B. MiYAZAWA 207 



after their germination. To decide between these two alternatives, ex- 

 periments were devised to test the germinating power of the seeds : they 

 were sown in a Peti'i dish containing sand, as well as in the field ; the 

 result was that almost all seeds were perfectly viable, because the rate 

 of their germination was 90 per cent, or even more. The first alternative 

 was thus proved to be untenable. Now to pass to the second : since 

 some young seedlings might die fi-om the severe cold of January and 

 February, some seeds derived fi-om dwarf and normal plants were .sown 

 in pots late January 1919 and placed in a cold frame to protect them 

 against severe cold. A certain number of seedlings were transplanted 

 into the field March 1st, because the frost in this month is generally only 

 slight in the vicinity of our Experiment Station, and various plants, 

 especially barley, begin then to grow vigorously, .so that there is no 

 more danger of their suffering from severe cold. In late April I dis- 

 covered among these plants a quite new dwarf fm-m, very different from 

 the dwarf described above. This new form produces a great many young 

 shoots ; thus in some cases 152 shoots were counted in a stock; its growth 

 is very slow, so that even in late April, when the ordinary dwarf plants 

 have attained their proper height and are alread}' ready to produce their 

 ear, we could hardly see in the new form any indication of the production 

 of the ears. Its height too was so low as to be easily mistaken for some 

 other graminaceous plant (see PI. XX. fig. 1), Even in late May or early 

 June none of these plants had produced any ear. All were seriously 

 attacked hy Erysiphe graminis and their growth became graflually poorer. 

 By the middle of June almost all of them died, whereas the other two 

 types had completed their growth. This new dwarf type which is unable 

 to produce an earl shall call sterile-dwarf m contradistinction to ordiiiaiy 

 dwarf form,s. 



The segi'egation observed in 1919 was as follows: 



We may therefore conclude as follows: even in the experiments of 

 1916, 1917, 1918, and 1919 a certain number of sterile-dwarf plants must 

 have appeared, but all of them died early under severe cold on aocoiiut 

 of their weak constitution, so that they escaped our observation. In the 

 experiment in which the seeds were sown in January 1919 they were 

 however protected against it and saved, so that tliey came under our 

 observation. 



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