(Department of Agronomy)

1. Illinois chemical strains.

The 49th generation of the Illinois exporiment on selection for chemical composition was grown in 1948. Mean analyses for the first and the last five generations of this experiment are shown in the following table:

	% oil		% protein
Year	High oil	Low oil	High protein	Low protein
1896	4.70	4.70	10.92	10.92
1940	12.57	1.36	19.92	6.19
1941	13.73	1.02	17.76	5.79
1945	12.62	1.53	17.60	6.27
1946	14.01	1.21	20.07	5.76
1947	13.45	.76	19.24	5.11

As a test of the genetic stability of these strains for chemical composition, after 48 generations of selection, a "reverse selection" experiment was begun in 1948. In addition to selection in the original directions, each strain is being selected for chemical composition in the opposite direction. The mean analyses of the seed lots used in starting "reverse selection" are shown in the following table:

	% oil		% protein
	High oil	Low oil	High protein	Low protein
Regular selection	14.61	.54	21.20	4.63
Reverse selection	11.79	1.03	16.63	5.93

C. M. Woodworth and Earl R. Leng