Inconstancy of Improved Races 775 



ears of corn or maize. The kernels are ar- 

 ranged in longitudinal rows, and these rows are 

 observed to occur in varying, but always even, 

 numbers. This latter circumstance is due to the 

 fact that each two neighboring rows contain 

 the lateral branches of a single row of spikelets, 

 the axes of which however, are included in the 

 fleshy body of the ear. The variation of the 

 number of the rows is easily seen to comply with 

 Quetelet's law, and often 30 or 40 ears suf- 

 fice to give a trustworthy curve. Fritz Miil- 

 ler made some experiments upon the inheritance 

 of the number of the rows, in Brazil. He chose 

 a race which averaged 12 rows, selected 

 ears with 14, 16 and 18 rows, etc., and sowed 

 their kernels separately. In each of these cul- 

 tures he counted the rows of the seeds on the 

 ears of all the plants when ripe, and calculated 

 their average. This average, of course, does 

 not necessarily correspond to a whole number, 

 and fractions should not be neglected. 



According to Vilmorin's rule he always found 

 some progression of the average and some re- 

 gression. Both were the larger, the more the 

 parent-ear differed from the general average, 

 but the proportion between both remained the 

 same, and seems independent of the amount of 

 the deviation. Putting the deviation at 5, 

 the progression calculated from his figures is 



