OATS 93 



mercial importance. The percentage of caryopsis does 

 not, however, decrease directly with the decrease in size 

 of combined caryopsis and hull, for the hull is much 

 thinner in some varieties having smaller sized kernels. 

 To give a good example, it was found in the results of an 

 extensive test that the large-kerneled heavy Swedish 

 Select variety usually weighed more per bushel and much 

 more per 100 kernels than the thin, long-kerneled Sixty 

 Day, but the latter possessed 1 per cent to 5 per cent 

 more of the caryopsis than the former. The usual pro- 

 portion for American varieties is about 70 per cent 

 (Warburton, 1910, pp. 9-12; Carleton, 1910, pp. 32-34). 



85. The origin of the common oats appears to be as 

 little known as that of wheat, though the latter is 

 without doubt more ancient. The difficulty in case of 

 this cereal is increased by a considerable confusion of 

 wild and cultivated forms. There is a prevailing opinion 

 at present that two species, Avena fatua, Linn., and A. 

 sterilis, Linn., have given rise to practically all cultivated 

 oats. The sterilis species is of more recent origin, and is 

 definitely located in the Mediterranean region, having 

 arisen in North Africa. The sativa species, which prob- 

 ably is derived from A. fatua and includes nearly all the 

 cultivated varieties, appears from the general trend of 

 all evidence to have originated in eastern temperate 

 Europe or western Asia. 



86. Present range. The extremes of latitude and 

 altitude for possible oat cultivation are not great. Spring 

 varieties are grown at considerable heights and rather 

 far north, but their range does not exceed that of wheat 

 in these respects and falls short of that of barley. Ex- 

 cepting the sterilis species, oats is somewhat inclined to 

 be a cold climate cereal, but only with respect to spring 



