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W. C. Etheridge 
type; nor can the latter be segregated as a class from so-called one-grained 
spikelets. which in reality are nothing less than extreme cases of double- 
grained spikelets. And, could such distinctions be established, there is 
no assurance that the classes thus arranged would remain constant under 
a change of environment. Bunger (1906) has found the number of spike- 
lots per panicle to vary greatly with the moisture content of the soil, and 
there is no reason to believe that the number of grains per spikelet would 
not vary also. 
In the present classification the number of grains in the spikelet is used 
only in a few special cases, when as between individual varieties of a small 
group there is a marked difference in respect to this character. In the 
detailed descriptions of varieties the prevailing number of grains is men- 
tioned merely as a record for this environment. 
MATURING PERIOD 
The maturing period, an important factor of the economic value of 
varieties, has a very limited use in classification. Varieties may be spoken 
of as early or late only in a relative sense, and not as actually defining a 
characteristic by which they may be identified. There is mutability of 
maturation in response to different climates and different soil conditions; 
and while for each variety there are also limits beyond which its ripen- 
ing period does not fluctuate, these cannot at present be accurately estab- 
lished. The data from comparative tests of varieties under different 
environments, by which a range in ripening periods might be fixed, are 
unfortunately often rendered untrustworthy by the confusion of varietal 
nomenclature. In this classification the writer is therefore limited to state- 
ments of the ripening periods of varieties only as applying to the present 
environment; such statements as a rule being for the most general pur- 
pose of description, although for the extremely early varieties Sixt}^- 
Day and Kherson the time required for ripening is used as a supplemen- 
tary means of distinction. 
COLOR OF GLUMES AT MATURITY 
The color of the ripened glume differs but little in cultivated varieties. 
Nilsson (1901) has distinguished pale golden from a deeper, brighter tone 
of the same color, and he uses the two shades of color in the description 
of single varieties. Kornicke and Werner (1885) often employed" the 
