No. 532] THE GEXOTYPES OF MAIZE 



251 



corn breeding, but only Professor ingersoll. 13 of Purdue 

 University, reported results. Professor Sanborn 12 ap- 

 parently performed similar experiments in the late eight- 

 ies at the Maine Agricultural Experiment Station. In 

 1892 G. W. McCluer 13 reported on a number of crosses 

 made during the preceding two years at the Illinois Agri- 

 cultural Experiment Station, and during the next two 

 years Morrow and Gardner 14 published bulletins from 

 the same station, describing the results of a number of 

 crosses. Apparently none of this work led to the subse- 

 quent utilization of hybridization methods in corn breed- 

 ing, as no work along this line appears to have been done 

 between the time when Morrow and Gardner issued their 

 second bulletin in 1893 and the publication of the first 

 report of my work with corn at the Station for Experi- 

 mental Evolution in 1908. The work of Beal, Ingersoll, 

 Sanborn, McCluer, and Morrow and Gardner showed that 

 increased yields from the hybrids, as compared with the 

 strains used for the crosses, are the almost invariable 

 result, though both McCluer, and Morrow and Gardner 

 found isolated instances in which the hybrids were in- 

 ferior to the parent strains. Hartley 1 -" lias since reported 

 that among a number of crosses made by the United 

 States Department of Agriculture also, some gave poorer 

 yields than the parent strains used for the cross, while 

 others gave superior yields, and reached the conclusion, 

 which 1 think is justified by my own results, that pro- 

 miscuous crossing is not necessarily advantageous but 

 that certain combinations lead to increased yields while 

 others may prove disadvantageous. Collins 10 has 



