356 The Philippine Journal of Science 1922 
The Philippine Islands, in common with other oriental rice- 
producing countries, presents a great wealth of varieties which 
have been classified into groups according to habitat or method 
of cultivation; namely, upland or lowland rice, awn or awn- 
less, glutinous or nonglutinous. This method of grouping is 
not strictly scientific; very often there is no definite or distinc- 
tive boundary line between several varieties. The designation 
of a variety as glutinous or nonglutinous, for instance, is not 
made by a certain definite and arbitrary standard of gluten, 
above which the sample falls into the glutinous group, and 
below into the nonglutinous; but, rather, long usage and custom 
predetermine the class. In some cases the coexistence of cer- 
tain physical characteristics of the grain places the sample in 
a certain group. Such physical characteristics include the shape 
(outline and thickness) of the grain, the length and width of 
the grain, the color of the hull and tips, the thickness of the 
hull, the color of the cuticle, the flavor, etc. In Table 1 these 
different characteristics for the twenty-three varieties under 
study, together with the origin, habitat, age of maturity, yield 
per hectare, and degree of popular acceptance are shown. 
It is interesting to note from this table that there is a close 
relationship between the length of maturity and the yield per 
hectare. The observation is also interesting in that it suggests 
a method of increasing the yield without expenditure of any 
special efforts. In general, the late-maturing varieties produce 
more per hectare than the early-maturing varieties. This fact 
would seem to be in line with the observations of Chambliss 
and Adams,” who showed that, by allowing the plant a longer time 
to mature, there resulted “an increase in yield and improvement 
in quality.” Thus, using the same variety for observation these 
authors found that Wateribune variety gave a yield of 5,350 
pounds per acre when allowed to mature in one hundred seventy- 
four days, and 7,020 pounds in two hundred two days; for Omachi 
variety, the yield obtained was 5,250 pounds in one hundred 
seventy-eight days, and 6,730 pounds in two hundred three days. 
A notable exception, however, is the Carolina Gold, which gave 
a yield of 4,300 pounds in one hundred eighty-seven days, an 
only 3,100 pounds in two hundred twelve days; this variety was 
not acclimatized in California but was grown there only experi- 
mentally. 
* Chambliss, Charles E., and Adams, E. L., Farmers’ Bull. U. 8. Dept. 
Agr. 688 (1915). 
