THE FOUNDATIONS OF ZOOLOGY 



Yellow corn is very variable in many respects. The number 

 of rows of kernels on the cob was, at the time M tiller made his 

 experiments, from 8 to 16; cobs with 10 or 12 rows being the 

 most common, while one with 18 or 20 rows was very seldom 

 found. After searching through several hundred cobs he found 

 one ear with 18 rows, but none with more. 



In 1867 he sowed, at different times, and in such a way as 

 to prevent crossing, (i) seed from the cob with 18 rows; (2) the 

 seed from the finest i6-rowed ear; and (3) the seed from the 

 finest 14-rowed ear. In 1868 he sowed (i) seed from a i6-rowed 

 ear which had grown from a i6-rowed ear; (2) seed from an 18- 

 rowed ear that had grown from i6-rowed seed; and (3) seed 

 from an i8-rowed ear from i8-rowed seed. In 1869 he sowed 

 (i) seed from an i8-rowed ear with i8-rowed parents and grand- 

 parents; (2) seed from a 2O-rowed ear with i8-rowed parents and 

 grandparents ; and (3) seed from a 22-rowed ear from seed from 

 an i8-rowed ear produced from seed from a i6-rowed ear. The 

 results are given in the following table : 



It will be seen from this table that the number of ears with 

 few rows decreases very rapidly in plants grown from seed taken 



