940 



SCIENCE 



[N. S. Vol. XXXVII. No. 964 



York State College of Forestry, Syracuse 

 University. 



At the Alabama Polyteclinic Institute, Au- 

 burn, Alabama, changes in the staff have 

 occurred as follows : Dr. E. P. Sandsten, pro- 

 fessor of horticulture and state horticulturist, 

 resigns to accept a similar appointment in 

 Colorado State College. A. B. Massey, for- 

 merly assistant professor of botany and bac- 

 teriology in Olemson College, becomes assist- 

 ant professor of botany. H. N. Conolly, field 

 agent in horticulture, resigns to accept similar 

 work in Colorado State College. Charles S. 

 Williamson, Jr., formerly assistant professor, 

 is promoted to associate professorship in the 

 department of chemistry. Jesse M. Jones is 

 appointed head of the department of animal 

 industry, succeeding Dan T. Gray, who has 

 accepted a similar position in the North Caro- 

 lina Agricultural College. 



The Board of Agricultural Studies of the 

 University of Cambridge, in consultation with 

 the president of the Royal Agricultural Soci- 

 ety, has nominated Mr. C. R. Fay, M.A., 

 Christ's College, to be the Gilbey lecturer on 

 the history and economics of agriculture. 



DISCUSSION AND COSBESPONDENCE 



THE CHARACTER OF THE ENDOSPERM OP SUGAR 

 CORN 



In a recent publication^ dealing with the 

 F, generation of a cross between two forms of 

 Zea Mays, the one with sugar endosperm, the 

 other with waxy endosperm, the existence of 

 two alternative factors, one for sugar (8), the 

 other for waxy (X) is assumed. Absence of 

 8 results in waxy endosperm, absence of X re- 

 sults in sugar endosperm. When both are 

 present a horny endosperm results. The F, 

 generation, involving 22,132 kernels, consisted 

 of those with horny, waxy and sugar endo- 

 sperm in a proportion closely approximating 

 the 9:3:4 ratio. 



The assumption of two alternative factors 



' Collins, G. N., and J. H. Kempton, ' ' Inherit- 

 ance of Waxy Endosperm in Hybrids with Sweet 

 Com," U. S. Dept. Agric, Bur. PI. Ind., Circular 

 120, 1913. 



does not meet the requirements, since on this 

 basis a ratio 9:3:3:1 is to he expected. On 

 the basis of Mr. Collins's theory, too, a zygotic 

 construction ssxx, involving I's of the F, gen- 

 eration should result in neither a waxy nor a 

 sugar endosperm. Yet the numerical results 

 clearly indicate a sugar endosperm for this 

 portion of the F, generation. (" Careful 

 scrutiny of the sweet seeds failed to show any 

 consistent differences that would allow another 

 class to be separated, . . .")• 



A more plausible explanation suggests itself 

 in an analogy to Cuenot's hybrids between 

 agouti and albino mice. Assuming a basic 

 factor 8, responsible for the sugar endosperm, 

 a factor W, which, acting together with 8, 

 produces a waxy endosperm, and a modifying 

 factor H, which acting together with the fac- 

 tors W and 8 produces a horny endosperm, I 

 would suggest for the zygotic constitution of 

 sugar corn IIRwwS8, and for the zygotic 

 constitution of Zea Mays with waxy endo- 

 sperm hhWWSS. On this basis the F^ gen- 

 eration of a cross sugar X waxy should pos- 

 sess the zygotic constitution HhWivSS, which, 

 according to our premises, should result, and 

 in fact does result, in a horny endosperm. 

 Selfing of the Fj generation should yield the 

 following combinations : 



The combinations EHWW88 (1), HnWw88 

 (2), HhWW88 (2) and HhWw88 (4), should 

 result in a horny endosperm, since they con- 

 tain all three factors; the combinations 

 EEww88 (1), Ehww88 (2) and hhww8S 

 (1), should yield a sugar endosperm, since the 

 factor W is lacking, and the combinations 

 hhWW88 (1) and hhWwSS (2) should pro- 

 duce a waxy endosperm, since the modifying 



