190 
The principles involved in Mendel’s theory of heredity and 
in De Vries’ mutation theory are well understood and are ex- 
tensively applied in their breeding work. In applying Men- 
del’s theory to rice hybrids, a large number of crosses have 
given results agreeing closely with those which Mendel and 
other workers in other crops have obtained. The practical 
application of these theories in breeding work is anticipated 
with greater assurance than ever, and already a number of 
valuable crosses have been effected. Plate C shows the 
parents and resultant cross of one of the most promising of 
these. 
In extensive plantings of pure strains, exceptional oppor- 
tunity is afforded for the study of mutations and this phase 
of research is not being neglected. It is interesting to note 
that during the season just past the most careful search of the 
entire fields, in which there were fully half a million plants, 
discovered less than one hundred mutations and natural hy- 
brids, these variations doubtlessly including also some 
“rogues.” This indicates two things : first, that mutations 
are extremely rare in the rice plant ; and, second, that natural 
crossing is exceptional — a fact confirmed by the writer’s ex- 
periments some years ago. The publication of this view, 
however, brought a good deal of criticism from some 
quarters. 
Whenever a superior new variety is developed, or an old 
strain improved, seed of it is distributed among the Prefec- 
ture Demonstration Stations in the rice-growing sections, 
first where the plant is grown for at least two seasons. If 
promising, or at least superior to the rices already grown, 
the seed is distributed among the farmers for general culti- 
vation. A number of the best varieties now growing in Japan 
were developed in this way, and their high quality is main- 
tained by Government inspection. The whole system is an 
admirable one, worthy of adoption in Hawaii. 
II. Insects and Fungus Diseases Affecting Rice. 
Japan has a serious problem in the wide dissemination of 
the insect pests and fungus diseases of the rice plant. 
Aside from the outbreak of the army-worm, Heliophila uni- 
puncta, last year, Hawaiian rice has been singularly free from 
insect pests or fungus diseases. For this very reason it seems 
important to the writer that a warning should be sounded as 
to the danger there is to our rice industry in the Japanese 
pests. Since the time that certain imported Japan milled rice 
was refused landing at Honolulu, in 1907, the Rice Export 
Association of Japan has taken every possible precaution to 
prevent the exportation of infested grain, but far more serious 
than the grain pests are the insects and fungus diseases which 
affect the plant. The most serious of these are two lepidop- 
