C. N. CKI.MNS (M, .1, II. M':\II'T()\. IMIKIIII'ANCK lll'' WAW KMllISI'KliM. .li'.l 



ralioii se^TL'yales sliuwcd a lai-^ei- |)ci-cciilai;e oi' waxy sceds ainoiiy- llic colorod 

 llian atnong Ihe wliile seeds. In ollicr words, there is a positive correialion 

 belwecn llie Iwo endosperm characlers Ihat hâve been assorialed in (lie parental 

 strains. 



.Nohn-c <•!' Ciirrrln/ioii.-:. 



Associali<iii in liic |iarenl sirains sccms nol to liav(> been considered as a 

 cause of eorreialion, tliougii tlie existence ol' such association lias been noted in 

 cases ascribed to i>ametic couplingand liere il lias been assutned Ihat Ihe asso- 

 ciation was duc to some sort of an affinity between the chararters as such. A 

 siniilar phenomenon has been described by Gook ' in cotlon hybrids and termed 

 " cohérence '' to distinguish it from other forms of corrélation. In cotton, 

 however, il has not been possible to secure parental strains possessing Ihe oppo- 

 site combinalion of characlers and Ihus preckide Ihe possibilily of gamelic cou- 

 |)ling. Examples of cohesjonare numerous; in tact, niost of the cases previously 

 described as " coherilal " -, " zygolitic "' ', or " gamelic " ', corrélations appear 

 to beof this nature. 



The emphasis, however, hasalways been placed on tlie idea thaï the corré- 

 lation was gamelic and due to an association of the characlers in transmission. 

 If characlers are considered as unchangeable iinils il was nalural thaï an inhe- 

 rited corrélation should be looked upon as a property of the characlers. The 

 réversible nature of Ihe corrélation in the case of lliese Chinese maize hybrids 

 forces us to enlertain the idea thaï the characlers are nolininiulable but maybe 

 modified in expression by Iheir association in Ihe zygote wilh olher characlers. 



In the crosses belween white Chinese and colored American varietics, the 

 resulls inighl be ascribed to gamelic coupling, but where the opposite cross is 

 madeanda colored Chineseiscrossedwilh a wliile American variely the correialion 

 is belween a dominant and a récessive characler. On the présence and absence 

 hypothesis,lhis in volves Ihe absurd assumplion of a présent characler being cou- 

 pied with one which is absent, a complication which disappears if alternative 

 inheri lance is looked upon as phenomenon of expression insteadof transmission '. 



Neilhercan the resultsbebi'ougiit under the liead of spuriousallelomorphism, 

 sinceallfourcombinalions of characlers oecur; Ihat is.l lie correialion is nol perfecl. 



Il may be urged thaï the aleurone color in the Chinese is a unit characler 

 distinct from tlie aleurone color in our American varielies with dilïerent affîni- 

 lies and lliat gamelic coupling exists between the waxy endosperm and Ihe Chi- 

 nese color. This possibilily is being invesligaled in experinients now under 

 way. Il liic ciiaraclersare unchangeable Ihere should be no sensible différence 

 in the correialion as a resuit of repeatedly selectinga combinalion of characlers 

 which originally showed a négative corrélation. 



Corrcliilian a/ Xciiin t'Imracli'rs. 

 The experim(Mils i'i'|)orle(l liere are, ^o far as known, Ihe lirst instance of a 



1. CouK (U.-F.;. Iliillrlii: li7. .Siippi-ussuil ;iihI IiilniMlicil l.:ii;n-aicis il] Cnlldii llUiri.ls. Itiinnii 

 of Plunt Induslni V. S. Deiil. of Aiirinillure. l'JO'.l. 



2. WEBm.;ii(ll'.-.l.). CdiTelalionof Characlers in l'Iiiiil lli .•clni-. Ain. Ureedeis Assiir.. Il, lOOCi. p. 7.">. 

 ô. GoiiuiiNs (C). lîel)er levknjeiihaslai'de, ziii- KcMiiliii-- ili'r (iivnzen der Mcinjcr^clu^ii lloscln. 



Bol. Ceiilrlh , LXXXIII Itaiirl, 1900, p. tOO. 



4. E.4ST (E.-M.). Oi-gaiiic Corrélations, l'ivr. Aiin'r. Ilm-.lrrs .^.^■.^<.(■., IV, l'.MI.S, |,|,. :,:,'> -7, IT, . 



5. CooK :'0,-l".). Ti-ansniissinn inlici-ilaiicc dislinfinislicil Ironi Kxi>ressii>M Inlii'i-jlniicr, Sririn-r ,\'. .S., 

 25. 911, 19u7. 



