328 IV ((iNKKItKNCK INTI•;H^AT10^ AI.K llK I.KNKTlnlJK. 



RIGHT AND LEFT HANDEDNESS IN CEREALS' 

 By R. H. COMPTON 



r,(i]ivillc> an.l CaiusCullogiM Camliiiil;,'.' (Kii-laiiili. 



TliP leaves of miny (Iramineao aro foldeil wlien young so llial one margin 

 overlaps the otlier. Two ilireclioiis of l'olding are possible, Ihese being relatcil 

 to one anolher as an objecl lo ils niirror imago. If we suppose an observer 

 plaeed in the axis of a young leaf wilh his back loward liie midrijj. and if tiie 

 margin of the leaf towanis his right hand overlaps the margin on his left. Ihe 

 Icaf may be called righl-handed (H H) : the reverse case being called lefl- 

 handed (L H). 



Normally, Ihe successive leaves ou a single stem are allernately R H 

 and L H, thougb occasional reversais are found. If \ve consider Ihe lirsl leaf 

 above the coleoplile alone it is possible to speak of RH and LH seediings. 



If the détermination of a seedling to Ije R II or L II were purely a matler of 

 chance we shoiild expect an equal uumber of each sort to be présent in a suffi- 

 ciently large random collection of seediings. Experiments on T\vo-Ro\vcd 

 Barley (Honleiim (lislirlmm) shew that Ihis is not the case. For instance, 

 lô'i? seediings of « Guinness' Goldlliorpe » Rarley comprised 74(1 LH and 

 Ml R II; the percentage of LH seediings (0/0 L H) being ."t.'). 77. « Kinver Che- 

 valier » gave 4(>78 LH, .îôC'J RH ; 0/0LH = o8.18. « Plumage Corn . gave 

 2408 L H, 1604 R H ; 0/0 L II = 60.02. Altogether eight varieties of Two-Rowed 

 Rarley were studied, of which at least four were pure lines. AH gave a 

 marked excess of LH seediings — lowest in « Guinness' Goldthorpe », highesl 

 in « Plumage Corn ». The total number of seediings examined, of ail varielics, 

 was 19 165, of which 1 1 180 were LH, 7080 RH : LH = 58.362. 



The possibility suggested itself Ihat the fold of the first leaf of IheofTspring 

 might be to some extent determined by the position of the seed on the pareni 

 spike. Experiments were made lo lest this. The two rows of seed on Ihe 

 spike of Horili'iim dislichiim may be distinguished as « odd » and « even « : 

 counting the alternate spikelets from Itelow upwards (including the first two or 

 lliree stérile ones), the row containing Nos. I, o, 5.... is called « odd ». the row 

 conlaining \os 2, 4. 6... « even ». The experinient was made of sowing seed 

 from the rows separately, and the foUowing results were oblained wifh <• Kinver 

 Chevalier ». The odd rows gave 867 LH, 615 RH; 0/0 LH =58.i5. The even 

 rows gave 2702 LH, 1042 RH ; 0/0 LH = 58.10. There is thus no évident con- 

 nection between the leaf-fold and the position on the parent spike. Similar 

 results were given by over 4000 seediings of « Plumage Corn ». Moreover, 

 many spikes were studied in détail, the position of each seed being considered. 

 but no orderly arrangement was discovered. 



The question whethcr the fold of the last leaf below Ihe spike has any 

 influence on the offspring was also answered in the négative 



•1. Communication failo à la deuxième séance de la Conférence. 



'2. The fiill dcsoriplion of llie following observations is piililislied paillv in ilic /',,„■. l'.iniiljriilgc 

 l'hll. Soc . vul. \V. p. 495, iniO; |iarlly in tin' .I<mni,il „f GriirUr.-^. vol. II. p. 53. l'.H-J. 



