Variation and Correlation of Oats — Part II 153 



The differences produced in the correlation coefficients by differences 

 in the growing conditions may amount to more than any varietal differences 

 that have been observed in the course of this work. By reference to Table 

 6 it is seen that the range of the differences between the correlation 

 coefficients of different varieties is from .030 to .184, while by reference 

 to Table 9 it is seen that the range of the differences between the cor- 

 relation coefficients of plants of the same variety grown in drills and in 

 hills is from .002 to .391. Thus the constants obtained by different 

 investigators are comparable only in so far as the conditions of growth are 

 comparable. 



Effect of different degrees of crowding on hiometrical constants of oats 



Are variation and correlation of oats modified by different degrees of 

 crowding in the row? In other words, do oat plants develop in the same 

 way when they are crowded together as thickly as they can stand, as 

 when they are less crowded? 



In order to answer these questions, plantings of two pure lines of oats 

 were made in eighteen-foot rows, side by side, on as uniform soil as could 

 be found. One variety was Sixty Day, pure line 62-II-19-2, which had 

 been grown twice from an individual plant and had been propagated for 

 several years by the Department of Plant-Breeding at Cornell University. 

 The other variety was originated by crossing Sixty Day and Probsteier, 

 this having been done some eight or ten years previously. This line, 

 known as 50al-18-2, was twice selected from the progeny of the cross, 

 and is very uniform. It also has been grown for several years by the 

 Department of Plant-Breeding. 



Three different rates of sowings of these lines were made. Lots of 

 386 kernels and 1000 kernels each were counted out and weighed. Then 

 in each line 40.45 grams was weighed, and the kernels in these weighings 

 were counted. The number of kernels and the weight of the same, for 

 each variety, sown in each eighteen-foot row, are given in the following 

 table, together with the series numbers by which the different sowings 

 are to be known: 



