No. 507] DEVELOPMENT AND HEREDITY 179 



indication of the comparative vigor of each strain was 

 obtained. Unfortunately crows and chipmunks played 

 havoc with the " stand" in a number of cases, and ac- 

 curate figures can not be given except in the following 

 four cases where the stand was perfect. 



A white dent no. 8 yielded 121 bushels per acre (at 70 

 pounds per bushel) ; a yellow dent no. 7, which had been 

 inbred artificially for three years, yielded 62 bushels per 

 acre ; the cross between the two varieties, no. 7 $ X no. 

 8 cf, yielded 142 bushels per acre. 



Longfellow, no. 34, an eight-rowed, yellow flint yield- 

 ing 72 bushels per acre, was crossed with the same no. 8 

 white dent, yielding 121 bushels per acre; the resulting 

 cross yielded 124 bushels per acre. 



Sturges's hybrid, a twelve-rowed, yellow flint with a 

 tall, non-branching stalk partaking of the characters of 

 dent varieties, was also crossed with no. 8 white dent. 

 The flint parent yielded 48 bushels per acre, while the 

 cross yielded 130 bushels per acre. 



Two families of a yellow dent variety, which had each 

 been inbred artificially for three years, were the parents 

 of the fourth cross. No. 12, yielding 65 bushels per acre, 

 was crossed with no. 7, yielding 62 bushels per acre. 

 The F 1 generation yielded 202 bushels per acre. This 

 last result is somewhat distorted, as five stalks per hill 

 of the cross were allowed to grow while of the parents 

 only four seeds per hill were planted. About 90 per 

 cent, of the seeds produced mature stalks. Notwith- 

 standing the closeness of planting to which this cross 

 was subjected, however, casual observation was sufficient 

 to show that it soared far beyond each parent in vigor 

 of plant and size of ear. 



In the remainder of the field every possible combina- 

 tion of dent, flint and sweet maize was grown, and in 

 every case an increase in vigor over the parents was 

 shown by the crosses. It is to be regretted that com- 

 parable yields could not be obtained in every instance, 

 but, as a matter of fact, the differences were so apparent 



