548 IV- CONFKItr.NCK INÏI.IIN ATKiN Al.K hi; l.lvMniUI K. 



Iho cnliro secd boinf^' liorn\ . Tliiis Inc llic \\;i\y cmlosporm bas l)eon foiiiKl 

 oiily in llio recenlly inlroduccd C.liinesc iiiai/c wlicre it occupics tlie saine |mi- 

 silion as does Ihc horny enddsjiciin in tlio llinl and pop varieties and snrronnds 

 a very sniall starcliy porlion. in swccl variclies lliere is aiso a small slarciiy 

 portion surrounded i^y a dense lioiny iayei- lii.it slirini<sin dryin^ and lal<es on 

 a giassy appearance. 



Tlie distinction betwecn liorny and slarciiy endosperm is w('ll marivcd and 

 in liiis sensé tlieir inlierilance is alternative. Both may, hovvever, occur in ilie 

 same secd and tlie relative proportion ol' llie Iwo lypes may vary greally in 

 difi'erent seeds from Ihc same ear, llie liorny puilion being usually greater in 

 llie seeds from the tip of tho ear. Tlie proportion ol' horny endosperm can 

 also be increased by subjecting tlie seeds to pressure when they are maturing. 

 Gompared with the starchy endosperm, the sweet endosperm behaves in the 

 same way as the horny and is subject 1o the same fluctuations. 



The inheritance of waxy and horny endosperm is alternative in quite 

 anolher sensé. They occupy homologous positions and bolh hâve never been 

 l'ound in the same seed. 



Tiiis waxy or cereons endosperm is as dislincl from theeorneous endosperm 

 of the American varieties as the corneous endosperm is from the aniylaceous 

 or starchy. Nothing approxiinating the lexture of the Chinese type lias been 

 found in any olher variety, Ihoiigh an exceplionally large séries of types from 

 ail paris of the world bave been examined whith this characler in mind. The 

 présent paper describes the liehavior of the endosperm characters in hybrids 

 lietwecn tliis and American variclies. 



The original importation of the Cliinese maize conlained both wliite seeds 

 and seeds with a maroon colored idcninnc. Planted separately and sclf-iiolli- 

 naled, bolii kinds bred Irue and ail seeds possessed the waxy endosperm. 



In llie lirsl or xenia génération of hylirids bet^veen Chinese corn and .\me- 

 ricaii \arieties with horny endosperm, the horny character was compleleiy 

 dominant in the entire séries of crosses, comprising abont KMI dilTerent varie- 

 lies, including al! the well-known types. 



This complète dominance made it appear probable thaï in Ihc second géné- 

 ration the characters would segregale in accordance with Mendelian ratios. 

 In Ihe second génération, secured by self-|)ollinating firsl génération hybrid 

 planis, the waxy characler reapiieared apparenlly unchanged in a part of the 

 seeds of each ear. The waxy to non-waxy seeds approximatcd on the average 

 the Mendelian monohybrid ralio of 1 : o. The percenlages of waxy seeds on 

 the individual ears, however, ranged from 15. i to 5."). \. The number of seeds 

 in each of llie ears was too large to permit thèse déviations to be ascribed to 

 chance, wliile llie ratios Cor tlie dilferenl ears varied by such small amounts 

 that to acconiil ïo\- Ihe resiills by supposing the appearance of Ihe characler 

 to dépend on a coml)ination of distinct faclors would necessilale the 

 assumption of a dilferenl gamelic formule for nearly every ear. 



When the colored and while seeds in the second génération were examined 

 separately il was found Ihal where a while strain of the Chinese had been 

 crossed with an American variely willi (dlored aleui'one thaï the \\hite seeds 

 carried a inuch higher percenlage of waxy seeds Ihan did the colored seeds. 

 On the olher hand, when a plani from a Chinese seed ^\ilh colored aleurone 

 was crossed wilh American varieties witli colorless aleurone, Ihe second gène- 



